ROC827 Remote Operations Controller

ROC827 Instruction Manual

Table 3-1. 12 Volt dc Power Input Terminal Block Connections

Terminal Blocks

BAT+ and BAT–

Definition

Accepts 12 Volts dc nominal from an

AC/DC converter or other 12 Volts dc supply.

Volts DC

Absolute Maximum: 11.25 to 16 Volts dc

CHG+ and CHG–

AUX+ and AUX–

Analog Input used to monitor an external charging source.

Supplies reverse polarity protected source voltage to external devices. Fused.

AUX

SW

+ and AUX

SW

– Supplies switched power for external devices.

11.25 to 14.25 Volts dc

0 to 18 Volts dc

0 to 14.25 Volts dc

Table 3-2. 12 Volt DC Power Input LED Fault Indicators

Signal LED

V

OK

V

OFF

V

OVER

TEMP

Green LED on when voltage is in tolerance on BAT+ and BAT–.

Fault – Red LED on when the AUX

SW

+ output are disabled by the CPU control line.

Fault – Red LED on when AUX

SW

+ is disabled due to excess voltage on BAT+.

Fault – Red LED on when AUX

SW

+ output are disabled due to the excess temperature of the Power Input module.

3.1.2 24-Volt DC Power Input Module (PM-24)

Using the PM-24, the ROC827 can accept 24 Volts dc (nominal) input power from an AC/DC converter or other 24 Volts dc supply connected to the + and – terminals. Connect the input power to either or both of the

+ and – channels. The 24 V dc Power Input module (PM-24) does not have CHG terminals for monitoring a charging voltage, and does not monitor the input voltage for alarming, sleep mode, or other monitoring purposes. The module has two LEDs that indicate voltage is received at the backplane and the CPU (see Figure 3-2 and Tables 3-3 and 3-4).

The base system (CPU, power input, and backplane) requires less than 70 mA. The Power Input module economizes power consumption using 3.3

Volts dc switching power that provides power to the I/O and communications modules installed in the ROC827 and any expanded backplanes. With this Power Input module installed, the ROC827 requires

20 to 30 Volts dc for proper operation.

Use the AUX+ and AUX– terminals to supply reverse polarity protected source voltage to external devices, such as a radio or solenoid.

Issued Mar-06 Power Connections 3-3


+ / –

AUX+ / AUX–

V

12

LED

V

3

LED

Figure 3-2. 24 Volt dc Power Input Module

Table 3-3. 24 Volt dc Power Input Terminal Block Connections

Terminal Blocks Definition

+ and – Accepts 24 Volts dc nominal from an AC/DC converter or other 24 Volts dc supply.

AUX+ and AUX– Supplies reverse polarity protected source voltage to external devices. Fused.

Volts DC

18 to 30 Volts dc

+12 Volts dc minus

∼0.7 Volts dc

Table 3-4. 24 Volt dc Power Input LED Indicators

Signal LED

V

12

V

3.3

Green LED on when voltage is provided to backplane.

Green LED on when voltage is provided to CPU.

3.1.3 Auxiliary Output (AUX+ and AUX–)

You can use the AUX+ and AUX– terminals to supply reverse polarity protected source voltage to external devices, such as a radio or a solenoid.

All module terminal blocks accept 12 AWG or smaller wiring. Refer to

Figures 3-3 and 3-4.

For the 12-volt dc Power Input module (PM-12), the auxiliary output follows the voltage located at BAT+ minus ~0.7 Volts dc, which is the protection diode voltage drop. For example, if the BAT+ voltage is 13 volts dc, then AUX+ is ~12.3 Volts dc.

For the 12-volt dc Power Input module, AUX+ / AUX– is always on and is current-limited by a fast acting glass 2.5 Amp x 20 mm fuse. In the event that the fuse blows, CSA requires that you replace the 2.5 Amp fast-acting fuse with a Little Fuse 217.025 or equivalent. Refer to

“Automatic Self Tests” in Chapter 1, General Information.



Power Supply

Terminal Block

AUXsw

–

AUX

+ – +

For the 24 volt Power Input module (PM-24), the AUX voltage is always

12 Volts dc minus ~0.7 Volts. AUX+ / AUX– is internally current-limited by a 0.5 Amp Positive Temperature Coefficient (PTC).

If you need to cycle power to the radio or other device to reduce the load on the power source (a recommended practice when using batteries), use a Discrete Output (DO) module to switch power on and off. Refer to the

ROCLINK 800 Configuration Software User Manual (Form A6121).

2 Amp or less

Fast ActingFuse

Other Equipment

2.5 Amps Maximum

Current On. Non-switched

–

–

Other Equipment

14.5 Volts DC Maximum @ 0.5 Amps

Switched Power

809AUX.DSF

Figure 3-3. 12 Volt dc Auxiliary Power Wiring

Power Supply

Terminal Block

AUX

– +

Other Equipment

12 Volts DC Maximum @ 0.5 Amps

Current-Limited Always On

–

0.5 Amp or less

Fast Acting Fuse

809AUX24.DSF

Figure 3-4. 24 Volt dc Auxiliary Power Wiring

Removing the

Auxiliary Output Fuse

To remove the auxiliary output fuse:

Installing the Auxiliary

Output Fuse

1.

Perform the procedure described in Section 3.3, “Removing a Power

Input Module.”

2.

Remove the fuse located at F1 on the Power Input module.

To re-install the auxiliary output fuse:

1.

Replace the fuse located at F1 on the Power Input module.

2.

Perform the procedure described in Section 3.4, “Installing a Power

Input Module.”



The AUX

SW

+ and AUX

SW

– terminals on the 12 volt dc Power Input module (PM-12) provide switched power for external devices, such as radios. AUX

SW

+ is current-limited for protection of the power input and the external device via a 0.5 Amp nominal Positive Temperature

Coefficient (PTC). The AUX

SW

+ and AUX

SW

– terminals provide voltages from 0 to 14.25 Volts dc. AUX

SW

+ is turned off when the

ROC827 detects a software configurable voltage (LoLo Alarm) at the

BAT+ and BAT– terminals. All module terminal blocks accept 12 AWG or smaller wiring. Refer to Figure 3-3.

If the source voltage falls to a level below which reliable operation cannot be ensured, the hardware circuitry on the Power Input module automatically disables the AUX

SW

+ outputs. This activity occurs at approximately 8.85 Volts dc, and is based on the LoLo Alarm limit set for the System Battery Analog Input Point Number 1. The low input voltage detect circuit includes approximately 0.75 Volts dc of hysteresis between turn-off and turn-on levels.

The presence of high input voltage can damage the linear regulator. If the dc input voltage at BAT+ exceeds 16 volts, the over-voltage detect circuit automatically disables the linear regulator, shutting off the unit. For further information on the STATUS LED functions, refer to Table 2-2 in

Chapter 2, Installation and Use.



3.2 Determining Power Consumption

Determining the power consumption requirements for a ROC827 configuration involves the following steps:

1.

Determine your ideal ROC827 configuration, which includes identifying all modules, device relays, meters, solenoids, radios, transmitters, and other devices that may receive DC power from the complete ROC827 configuration (base unit and EXPs).

Note

: You should also identify any devices (such as a touch screen panel) that may be powered by the same system but not necessarily by the ROC827.

2.

Calculate the “worst-case” DC power consumption for that configuration by totaling the combined power draw required for all installed modules, as well as accounting for the power any modules provide to external devices (through the use of +T).

Note

: “+T” describes the isolated power some modules (such as AI,

AO, PI, and HART) may supply to external devices, such as 4–20 mA pressure and temperature transducers.

3.

Verify that the power input module you intend to use can meet the power requirements calculated in the first step.

This verification helps you identify and anticipate power demands from +T external devices that exceed the capabilities of the PM-12 or

PM-24 Power Input modules. In this case, you can then make arrangements to externally power these field devices.

4.

“Tune” (if necessary) the configuration by providing external power or re-assessing the configuration to lessen the power requirements from the ROC827.

To assist you in this process, this chapter contains a series of worksheets

(Tables 3-5 through 3-16) that help you to identify and assess the power requirements for each component of your ROC827 system. Table 3-5 identifies the power requirements related to the ROC827 base unit and summarizes the power requirements you identify on Tables 3-6 through

3-16. (Complete Tables 3-6 through 3-15 to calculate the power consumption for each of the I/O modules, and then transfer those results to Table 3-5.) Completing Table 3-5 enables you to quickly determine whether the power input module you intend to use is sufficient for your configuration. If the power module is not sufficient, you can then review individual worksheets to determine how to best “tune” your configuration and lessen power demands.



General Calculation

Process

To calculate the power the ROC827 requires:

1.

Determine the kind and number of communication modules and the kind and number of expanded backplanes you are implementing.

Enter those values in the Quantity Used column of Table 3-5.

2.

Multiply the P

Typical

value by the Quantity Used. Enter the values in the Sub-Total column of Table 3-5. Perform this calculation for both the communications module and the LED.

3.

Determine the kind and number of I/O modules you are implementing and complete Tables 3-6 through 3-15 for those modules. For each applicable I/O module:

a.

Calculate the P

Typical

values and enter them in the P

Typical

columns of each table. Perform this calculation for the I/O modules, LEDs

(if applicable), channels (if applicable), and any other devices.

b.

Calculate the Duty Cycle value for each I/O module and each I/O channel (as applicable). Enter those values in the Duty Cycle column of Tables 3-6 through 3-15.

c.

Multiply the P

Typical

values by the Quantity Used by the Duty

Cycle on each applicable table. Enter those individual sub-totals in the Sub-Total column on each table and add the sub-totals to calculate the Total for the table.

4.

Transfer the totals from Tables 3-6 through 3-15 to their respective lines in the Sub-Total column on Table 3-5.

5.

Add the Sub-Total values for Tables 3-6 through 3-15. Enter that value in the Total for All Modules line on Table 3-5.

6.

Add the value from the Total for ROC827 Base Unit to the Total for

All Modules. Enter that result in the Total for ROC827 Base Unit and

All Modules line.

7.

Transfer the Other Devices total from Table 3-16 to its respective line in the Sub-Total column on Table 3-5.

8.

Add the values from Total for ROC827 Base Unit, Total for All

Modules, and the total for Other Devices. Enter that value in the Total for ROC827 Base Unit, All Modules, and Other Devices line.

9.

Multiply the value in the Total for ROC827 Base Unit, Total for All

Modules, and Other Devices by 0.25. Enter the result in the Power

System Safety Factor (0.25) line.

Note

: This value represents a safety factor to the power system to account for losses and other variables not factored into the power consumption calculations. This safety factor may vary depending on external influences. Adjust the factor value up or down accordingly.



10.

Add the values for the Power System Safety Factor (0.25) to the Total for ROC827 Base Unit, All Modules, and Other Devices to determine the total estimated power consumption for the configured ROC827 system.



AI Modules

AO Modules

DI Modules

DO Modules

DOR Modules

PI Modules

MVS Modules

RTD Modules

Thermocouple Modules

HART Modules

Other Devices

Table 3-5. Estimated Power Consumption

Device

CPU and ROC827 Backplane

Power Input Module PM-12

Power Input Module PM-24

Per Active LED – Maximum 10

EIA-232 (RS-232) Module


EIA-422/485 (RS-422/485) Module


Dial-up Modem Module


Expanded Backplanes

Power Consumption (mW)

Quantity

Used

Description P

TYPICAL

110 mA @ 12 volts dc 1320 mW

55 mA @ 24 volts dc 1320 mW

1.5 mA 18 mW

4 mA @ 12 volts dc

1.5 mA

48 mW

18 mW

112 mA @ 12 volts 1344 mW

1.5 mA 18 mW


1.5 mA 18 mW



Total for ROC827 Base Unit

Total (from Table 3-6)










Total for All Modules

Total for ROC827 Base Unit and All Modules


Total for ROC827 Base Unit, All Modules, and

Other Devices

Power System Safety Factor (0.25)

Total for Configured ROC827

Sub-Total

(mW)

mW

mW

mW

mW

mW

mW

mW



3.2.1 Tuning the Configuration

The PM-12 Power Input module can supply a maximum of 36 W (36000 mW) to the backplane, which includes the +T overhead. The PM-24, when operating between –40

°C to 55°C, can supply a maximum of 30 W

(30000 mW) to the backplane. Across its entire operating range (–40

°C to

85

°C) the PM-24 can supply 24 W (24000 mW).

Refer to Table 3-5 and the value you entered in the Total for ROC827

Base Unit and All Modules line. That is the value against which you

“tune” your configuration to accommodate your Power Input module. If your configuration requires more power than the Power Input module you intend to use, you need to modify your I/O module configuration to reduce your power requirements.

Tuning Hints

Review the content of Tables 3-6 through 3-15. Suggestions to help you better align the configuration of your ROC827 with the capability of the Power Input module you intend to use include:

Reduce the +T usage by providing an external power supply for as many transmitters or field devices needed to reduce the value in the

Total for ROC827 Base Unit and All Modules line on Table 3-5 to below the capability of the Power Input module you intend to use.

Reduce the +T usage by reducing the number of transmitters or field devices.

Reduce the total number of I/O modules by consolidating transmitters or field devices onto as few I/O modules as possible.

Note

: Tuning your I/O module configuration may require several iterations to rework the content of Tables 3-6 through 3-15 until your power requirements match the capability of the Power Input module you intend to use.



Table 3-6. Power Consumption of the Analog Input Modules

I/O Module


Description P

TYPICAL

ANALOG INPUT

AI Module Base

Jumper set for +T @ 12 volts dc


Channel 1

Channel 2

Channel’s mA current draw from +T * 1.25 * 12


Channel 3

Channel 4




Channel 1

Channel 2

Channel 3

Channel 4





Quantity

Used

Duty

Cycle

Table Total

Sub-Total

(mW)

Duty Cycle

The duty cycle is based on the average current flow compared to the full-scale current flow value. To approximate the duty cycle, estimate the average current consumption in relation to its maximum range. For example, if an AI channel’s current averages 16 mA:

Duty Cycle = Average mA output

÷ Maximum mA Output = (16 ÷ 20) = 0.80



Table 3-7. Power Consumption of the Analog Output Modules

I/O Module


Description P

TYPICAL

AO Module Base

100 mA @ 12 volts dc 1200 mW


Channel 1

Channel 2



Channel 3

Channel 4




Channel 1


Channel 2

Channel 3

Channel 4




Quantity

Used

Duty

Cycle

Table Total

Sub-Total

(mW)

Duty Cycle

The duty cycle is based on the average current flow compared to the full-scale current flow value. To approximate the duty cycle, estimate the average current consumption in relation to its maximum range. For example, if an AO channel’s current averages 12 mA:

Duty Cycle = Average mA output

÷ Maximum mA Output = (12 ÷ 20) = 0.60



Table 3-8. Power Consumption of the Discrete Input Modules

I/O Module

DI Module Base

Channel 1

Channel 2

Channel 3

Channel 4

Channel 5

Channel 6

Channel 7

Channel 8

Per Active LED –

Maximum 8


Description P

TYPICAL

19 mA @ 12 volts dc No

Channels Active

228 mW

3.2 mA @ 12 volts dc 38.4 mW

3.2 mA @ 12 volts dc 38.4 mW

3.2 mA @ 12 volts dc 38.4 mW

3.2 mA @ 12 volts dc 38.4 mW

3.2 mA @ 12 volts dc 38.4 mW

3.2 mA @ 12 volts dc 38.4 mW

3.2 mA @ 12 volts dc 38.4 mW

3.2 mA @ 12 volts dc 38.4 mW

Quantity

Used

1.5 mA 18 mW

Duty

Cycle

Sub-Total

(mW)

Table Total

Duty Cycle

The duty cycle is the time on divided by the total time, and is essentially the percent of time that the I/O channel is active

(maximum power consumption).

Duty Cycle = Active time

÷ (Active time + Inactive time)

For example, if a Discrete Input is active for 15 seconds out of every 60 seconds:

Duty Cycle = 15 seconds

÷ (15 seconds + 45 seconds) = 15 seconds ÷ 60 seconds = 0.25



I/O Module

DO Module

Channel 1

Channel 2

Channel 3

Channel 4

Channel 5

Per Active LED –

Maximum 5

Table 3-9. Power Consumption of the Discrete Output Modules


Description P

TYPICAL


Channels Active

1.5 mA

1.5 mA

1.5 mA

1.5 mA

1.5 mA

240 mW

18 mW

18 mW

18 mW

18 mW

18 mW

Quantity

Used

1.5 mA 18 mW

Duty

Cycle

Table Total

Sub-Total

(mW)

Duty Cycle





For example, if a Discrete Output is active for 15 seconds out of every 60 seconds:

Duty Cycle = 15 seconds

÷ (15 seconds + 45 seconds) = 15 seconds ÷ 60 seconds = 0.25



DOR Module

Channel 1

Channel 2

Channel 3

Channel 4

Channel 5

Per Active LED –

Maximum 5

Table 3-10. Power Consumption of the Discrete Output Relay Modules

I/O Module


Description P

TYPICAL

6.8 mA @ 12 volts dc

No Channels Active

150 mA for 10 mSec during transition





1.5 mA

81.6 mW

1800 mW for 10 mSec

1800 mW for 10 mSec

1800 mW for 10 mSec

1800 mW for 10 mSec

1800 mW for 10 mSec

18 mW for

10 mSec

Quantity

Used

Duty

Cycle

Table Total

Sub-Total

(mW)

Duty Cycle

The duty cycle is:

[((Number of Transitions in some time period) * 0.01 sec)] ÷ (Seconds in the period) = Duty Cycle

For example, if a DOR channel changes state 80 times per hour:

80 = Number of transitions.

Hour is the time period.

An hour contains 3600 seconds.

Calculate the duty cycle as:

Duty Cycle = [(80 * 0.01) ÷ 3600] = 0.0002



Table 3-11. Power Consumption of the High and Low Speed Pulse Input Modules

I/O Module

PI Module

Channel 1

Channel 2

Per Active LED –

Maximum 4

Jumper set to +T @ 12 volts dc

Jumper set to +T @ 24 volts dc


Description P

TYPICAL


Channels Active

7.4 mA

7.4 mA

252 mW

88.8 mW

88.8 mW

Quantity

Used

18 mW 1.5 mA

1.25 * Measured Current

Draw at +T Terminal

2.5 * Measured Current

Draw at +T Terminal

Duty

Cycle

Table Total

Sub-Total

(mW)

Duty Cycle



Duty Cycle = [Active Time * (Signals Duty Cycle)] ÷ (Total Time Period)

For example, if a Pulse Input receives a signal for 6 hours over a 24-hour time period and the signal’s wave form is on time for 1/3 of the signal’s period:

Duty Cycle = [6 hours * (1 ÷ 3)] ÷ (24 hours) = 0.0825



Table 3-12. Power Consumption of the MVS Modules

I/O Module

MVS Module


Power provided by the module for the MVS sensors


Description P

TYPICAL

112 mA @ 12 volts dc 1344 mW

1.5 mA 18 mW

1.25 * Measured

Current Draw at +

Terminal

Quantity

Used

Duty

Cycle

1

Table Total

Sub-Total

(mW)

Note: For an MVS sensor, the typical mW per MVS is about 300 mW.

Duty Cycle

The duty cycle is the time on divided by the total time. For an MVS, the sensor is always drawing power, so enter the duty cycle as “1” for the MVS power calculations. The LEDs can also have an associated duty cycle, which is essentially the percent of time that the LEDs are active.



For example, if the LEDs are on approximately 20 minutes a day:

Duty Cycle = 20 minutes

÷ (24 * 60 minutes in a day) = 20 ÷ 1440 = 0.014



Table 3-13. Power Consumption of the RTD Modules

I/O Module


Quantity

Used

Duty

Cycle

Sub-Total

(mW)

RTD Module

Description P

TYPICAL

65 mA @ 13.25 volts dc 1

Table Total

Duty Cycle

An RTD has no associated duty cycle. Consequently, always set “1” as the duty cycle value.

Table 3-14. Power Consumption of the Thermocouple Modules

I/O Module


Description P

TYPICAL

Quantity

Used

Duty

Cycle

Sub-Total

(mW)

TYPE J OR K THERMOCOUPLE MODULE

T/C Module

84 mA @ 12 volts dc 1008 mW 1

Table Total

Duty Cycle

A thermocouple has no associated duty cycle. Consequently, always set “1” as the duty cycle value.

Table 3-15. Power Consumption of the HART Modules

Other Device

HART Module Base

Each Channel


Description P

TYPICAL

110 mA @ 12 volts dc


1320 mW

Quantity

Used

Duty

Cycle

Table Total

Sub-Total

(mW)



Other Device

Table 3-16. Power Consumption of Other Devices


Description P

TYPICAL

Quantity

Used

Duty

Cycle

Total

Sub-Total

(mW)

Although Tables 3-5 and Tables 3-6 through 3-15 take into account the power the ROC827 supplies to its connected devices, be sure to add the power consumption (in mW) of any other devices (such as radios or solenoids) used with the ROC827 in the same power system, but which are not accounted for in Tables 3-6 through 3-15.

Enter that Total value in the Other Devices line of Table 3-5.

3.3 Removing a Power Input Module

Caution

To remove the Power Input module:

Failure to exercise proper electrostatic discharge precautions, such as wearing a grounded wrist strap may reset the processor or damage electronic components, resulting in interrupted operations.

When working on units located in a hazardous area (where explosive gases may be present), make sure the area is in a non-hazardous state before performing procedures. Performing these procedures in a hazardous area could result in personal injury or property damage.

1.

Perform the backup procedure described in “Preserving Configuration and Log Data” in Chapter 6, Troubleshooting.

2.

Remove power from the ROC827.

3.

Remove the wire channel cover.

4.

Unscrew the two captive screws on the front of the Power Input module.

5.

Remove the Power Input module.

Note

: If you intend to store the ROC827 for an extended period, also

remove the internal backup battery.



3.4 Installing a Power Input Module

Caution

To install the Power Input module:



Note

: Remove the plastic module cover and wire channel cover, if

present.

1.

Slide the Power Input module into the slot.

2.

Press the module firmly into the slot. Make sure the connectors at the back of the Power Input module fit into the connectors on the backplane.

3.

Tighten the two captive screws on the front of the Power Input module firmly (refer to Figures 3-1 and 3-2).

4.

Replace the wire channel cover.

5.

Review “Restarting the ROC827” in Section 6, Troubleshooting.

6.

Return power to the ROC827.

3.5 Connecting the ROC827 to Wiring

Caution

The following paragraphs describe how to connect the ROC827 to power.

Use the recommendations and procedures described in the following paragraphs to avoid damage to equipment.

Use 12 American Wire Gauge (AWG) wire or smaller for all power wiring.

Always turn off the power to the ROC827 before you attempt any type of wiring. Wiring of powered equipment could result in personal injury or property damage.

To avoid circuit damage when working with the unit, use appropriate electrostatic discharge precautions, such as wearing a grounded wrist strap.

To connect the wire to the removable block compression terminals:

1.

Bare the end (¼ inch maximum) of the wire.

2.

Insert the bared end into the clamp beneath the termination screw.

3.

Tighten the screw.



The ROC827 should have a minimum of bare wire exposed to prevent short circuits. Allow some slack when making connections to prevent strain.

3.5.1 Wiring the DC Power Input Module

Use 12 American Wire Gauge (AWG) wire or smaller for all power wiring. It is important to use good wiring practice when sizing, routing, and connecting power wiring. All wiring must conform to state, local, and

NEC codes.

Verify the hook-up polarity is correct.

To make DC power supply connections:

1.


2.

Install a surge protection device at the service disconnect.

3.

Remove all other power sources from the ROC827.

4.

Install a fuse at the input power source.

5.

Remove the terminal block connector from the socket.

6.

Insert each bared wire end from either the:

12 Volts dc source into the clamp beneath the appropriate BAT+ /

BAT– termination screw.

24 Volts dc source into the clamp beneath the appropriate BAT+ /

BAT– termination screw. The + terminal should have a similar fuse to the 12 Volts dc Power Input Module.

– CHG+ – BAT+

Issued Mar-06

5 Amp Fuse

12 Volt DC Battery Bank

AC to 12 Volt DC Power Supply

24 Volt DC/12 Volt DC Power Converter

Other 12 Volt DC Nominal Source

BATWIRE.DSF

Figure 3-5. 12 Volts dc Power Supply and BAT+ / BAT– Wiring

7.

Screw each wire into the terminal block.

8.

Plug the terminal block connector back into the socket.

9.

If you are monitoring an external charge voltage (12 Volts dc Power

Input Module only), wire the CHG+ and CHG– terminal block connector. Refer to Figure 3-6.

Power Connections 3-22


Solar

Regulator

+

–

Batteries

+ –

+

– +

–

+

–

–

Solar

Panel

Power Supply

Terminal Block

– CHG+ – BAT+

5 Amp Fuse

5 Amp Fuse

809CHG.DSF

Figure 3-6. 12 Volt dc Power Supply and CHG+ and CHG– Wiring

10.

Replace all other power sources (if necessary) to the ROC827.

11.

Review “Restarting the ROC827” in Chapter 6, Troubleshooting.

Note

: Refer to Table 3-2 concerning LEDs.

3.5.2 Wiring the External Batteries

You can use external batteries as the main source of power for the

ROC827 with the 12 volts dc Power Input module (PM-12). The maximum voltage that can be applied to the BAT+ / BAT– terminals is

16 volts dc before damage may occur. The recommended maximum voltage is 14.5 volts dc (refer to Table 3-2 concerning LEDs).

It is important that you use good wiring practices when sizing, routing, and connecting power wiring. All wiring must conform to state, local, and

NEC codes. Use 12 American Wire Gauge (AWG) or smaller wire for all power wiring.

Batteries should be rechargeable, sealed, gel-cell, lead-acid batteries.

Connect batteries in parallel to achieve the required capacity (refer to

Figure 3-6). The amount of battery capacity required for a particular installation depends upon the power requirements of the equipment and days of reserve (autonomy) desired. Calculate battery requirements based on power consumption of the ROC827 and all devices powered by the batteries.



Battery Reserve

Battery reserve is the amount of time that the batteries can provide power without discharging below 20% of their total output capacity.

The battery reserve should be a minimum of five days, with ten days of reserve preferred. Add 24 hours of reserve capacity to allow for overnight discharge. Space limitations, cost, and output are all factors that determine the actual amount of battery capacity available.

To determine the system capacity requirements, multiply the system current load on the batteries by the amount of reserve time required, as shown in the following equation:

System Requirement = Current Load in Amps * Reserve Hours = _____ Amp Hours

Caution

When using batteries, apply in-line fusing to avoid damaging the ROC827.

To make battery connections:

1.


2.

Remove the BAT+ and BAT– terminal block connector from the socket.

3.

Install a fuse at the input power source.

4.

Insert each bared wire end into the clamp beneath the BAT+ and

BAT– termination screws (refer to Figure 3-5).

5.

Screw each wire into the terminal block.

6.


7.

Re-apply power to the ROC827.

Note

: Refer to Table 3-2 concerning LEDs.



3.5.3 Replacing the Internal Battery

The internal Sanyo 3 volt CR2430 lithium backup battery located on the

CPU provides backup of the data and the Real-Time Clock when the main power is not connected. The battery has a one-year minimum backup life while the battery is installed and no power is applied to the

ROC827. The battery has a ten-year backup life while the backup battery is installed and power is applied to ROC827 or when the battery is removed from the ROC827.

Recommended replacement Lithium/Manganese Dioxide batteries include:

Table 3-17. Replacement Battery Types

Issued Mar-06

Part

Size

Type

Capacity

Acceptable Types

Battery, Lithium, 3V

24 mm (0.94 in) diameter x 3 mm (0.12 in) height

Coin Type

280 mAh minimum

Sanyo CR2430

Varta CR2430

Note

: Remove the internal backup battery if you intend to store the

ROC827 for an extended period.

Caution

When working on units located in a hazardous area (where explosive gases may be present), make sure the area is in a non-hazardous state before performing these procedures. Performing these procedures in a hazardous area could result in personal injury or property damage.

To avoid circuit damage when working inside the unit, use appropriate electrostatic discharge precautions, such as wearing a grounded wrist strap.

1.


Note: Removing the battery erases the contents of the ROC827’s

RAM.

2.

Remove all power from the ROC827.

3.


4.

Remove the two screws on the CPU faceplate.

5.

Remove the CPU faceplate.

6.

Remove the CPU (as described in “Removing the CPU Module” in

Chapter 2, Installation and Use).

Power Connections 3-25


7.

Insert a plastic screwdriver behind the battery and gently push the battery out of the battery holder. Note how the battery is oriented: the negative side of the battery (–) is placed against the CPU and the positive (+) towards the + label on the battery holder.

8.

Insert the new battery in the battery holder paying close attention to install the battery with the correct orientation.

9.

Reinstall the CPU (as described in “Installing the CPU Module” in

Chapter 2, Installation and Use).

10.

Replace the CPU faceplate.

11.

Replace the two screws to secure the CPU faceplate.

12.


13.


14.

Apply power to the ROC827.

3.6 Related Specification Sheets

Refer to the following specification sheets (available at www.EmersonProcess.com/flow ) for additional and most-current information on the Power Input modules for the ROC827.

Table 3-18. Power Input Module Specification Sheets

Name

Power Input Modules (ROC800-Series)

Form Number

6.3:PIM

Part Number

D301192X012



Chapter 4 – Input/Output Modules

This chapter describes the Input/Output (I/O) modules used with the

ROC827 and expandable backplanes and contains information on installing, wiring, and removing the I/O modules.

In This Chapter

4.2 Installation................................................................................................4-3

4.2.1 Installing an I/O Module .................................................................4-4

4.2.2 Removing an I/O Module ...............................................................4-5

4.2.3 Wiring I/O Modules ........................................................................4-6

4.9.1 Connecting the RTD Wiring .........................................................4-15

4.10 J and K Type Thermocouple Input Modules..........................................4-16

4.1 I/O Module Overview

The I/O modules typically consist of a terminal block for field wiring and connectors to the backplane. The ROC827 base unit supports up to three

I/O modules. Each expandable backplane (EXP) can accommodate up to six I/O modules, and a fully configured ROC827 can handle up to 27 I/O modules (three on the base unit and six modules on each of up to four expandable backplanes). Each I/O module electrically connects to field wiring by a removable terminal block. Refer to Figures 4-1 and 4-2.

Note

: Figure 4-2 represents a ROC827 with one EXP.

Issued Mar-06 Input/Output Modules 4-1


DOC0513A

Front View Side View

Figure 4-1. Typical I/O Module

I/O Slot #1 or

Comm 3

I/O Slot #2 or

Comm 3 or 4

I/O Slot #3 or

Comm 3, 4, or 5

Issued Mar-06

Figure 4-2. Optional I/O Module Locations (ROC827 with one EXP)

I/O modules for the ROC827 include:

Analog Input (AI) modules that provide the ability to monitor various analog field values.

Discrete Input (DI) and Pulse Input (PI) modules that provide the ability to monitor various discrete and pulse input field values.

Input/Output Modules 4-2

I/O Slot #4

I/O Slot #7

I/O Slot #5

I/O Slot #8

I/O Slot #6

I/O Slot #9


Analog Output (AO), Discrete Output (DO), and Discrete Output

Relay (DOR) modules that provide the ability to manage various control devices.

The RTD Input and Thermocouple Input (T/C) modules that provide the ability to monitor various analog temperature field values.

The Highway Addressable Remote Transducer (HART) interface modules that enable the ROC827 to communicate with HART devices using the HART protocol as either Analog Inputs or Analog Outputs.

Each module rests in a module slot at the front of the ROC827 base unit or

EXP housing. You can easily install or remove I/O modules from the module slots while the ROC827 is powered up (hot-swappable). Modules may be installed directly into unused module slots (hot-pluggable), and modules are self-identifying in the software. All modules have removable terminal blocks to make servicing easy. I/O modules can be added in any module slot.

The I/O modules acquire power from the backplane. Each module has an isolated DC/DC converter that provides logic, control, and field power as required. The ROC827 has eliminated the need for fuses on the I/O modules through the extensive use of current-limited short-circuit protection and over voltage circuitry. Isolation is provided from other modules and the backplane, power, and signal isolation. The I/O modules are self-resetting after a fault clears.

4.2 Installation

Caution

Each I/O module installs in the ROC827 in the same manner. You can install any I/O module into any module socket, whether empty or in place of another module.


When installing units in a hazardous area, make sure all installation components selected are labeled for use in such areas. Installation and maintenance must be performed only when the area is known to be nonhazardous. Installation in a hazardous area could result in personal injury or property damage.

You can insert or remove the I/O modules while power is connected to the

ROC827. If the ROC827 is powered, exercise caution while performing the following steps to install a module.

Note

: After you install a new I/O module or replace an existing I/O

module, it may be necessary to reconfigure the ROC827. To change configuration parameters, use ROCLINK 800 software to make changes to the new module. Any added modules (new I/O points) start up with


ROC827 Instruction Manual default configurations. Refer to the ROCLINK 800 Configuration Software

User Manual (Form A6121).

4.2.1 Installing an I/O Module

To install an I/O module in either the ROC827 or the EXP:

1.


Note

: Leaving the wire channel cover in place can prevent the module

from correctly connecting to the socket on the backplane.

2.

Perform one of the following:

If there is a module currently in the slot, unscrew the captive screws and remove that module (refer to “Removing an I/O

Module”).

If the slot is currently empty, remove the module cover.

3.

Insert the new I/O module through the module slot on the front of the

ROC827 or EXP housing. Make sure the label on the front of the module faces right side up (refer to Figure 4-3). Gently slide the module in place until it contacts properly with the connectors on the backplane.

Note

: If the module stops and will not go any further, do not force the

module. Remove the module and see if the pins are bent. If the pins are bent, gently straighten the pins and re-insert the module. The back of the module must connect fully with the connectors on the backplane.



Figure 4-3. Installing an I/O Module

4.

Tighten the captive screws on the front of the module.

5.

Wire the I/O module (refer to “Wiring I/O Modules”).

Caution

6.


Never connect the sheath surrounding shielded wiring to a signal ground terminal or to the common terminal of an I/O module. Doing so makes the

I/O module susceptible to static discharge, which can permanently damage the module. Connect the shielded wiring sheath only to a suitable earth ground.

7.

Connect to ROCLINK 800 software and login. The I/O modules are self-identifying after re-connecting to ROCLINK 800 software.

8.

Configure the I/O point.

4.2.2 Removing an I/O Module

To remove an I/O module:

1.


2.

Unscrew the two captive screws holding the module in place.

3.

Gently pull the module’s lip out and remove the module from the slot.

You may need to gently wiggle the module.

4.

Install a new module or install the module cover.

5.

Screw the two captive screws to hold the module or cover in place.



6.


4.2.3 Wiring I/O Modules

All modules have removable terminal blocks for convenient wiring and servicing. The terminal blocks can accommodate a wide range of wire gauges (12 AWG or smaller).

Caution



1.


2.


3.

Tighten the screw.


Note

: All modules have removable terminal blocks for convenient wiring

and servicing. Twisted-pair cable is recommended for I/O signal wiring.

The removable terminal blocks accept 12 AWG or smaller wire.

4.3 Analog Input Modules

The four Analog Input (AI) channels are scalable, but typically measure either:

4- to 20-mA analog signal, with the use of a precision resistor

(supplied).

1 to 5 Volts dc signal.

If required, you can calibrate the low end of the analog signal to zero.

You can configure the AI (+T) module as either 12 or 24 Volt dc using jumper J4 on the I/O module (see Figure 4-4). The AI modules can provide isolated +12 Volt dc or +24 Volt dc field transmitter power on a per-module basis. For example, one module can provide +12 Volts dc for powering low power analog transmitters, while another module in the same ROC827 can provide +24 Volts dc for powering conventional 4- to

20-mA transmitters. Refer to Figure 4-5:



Precision

Resistor

Figure 4-4. Analog Input Jumper J4 – Set to +24V

OUT SIGNAL

+

COM

-

+

-

1-5 VOLT DEVICE

EXTERNALLY POWERED

1-5 VOLT DEVICE

EXTERNALLY POWERED

IN

-

+

CURRENT LOOP DEVICE 4-20mA

ROC809 POWERED

+T 12 / 24 V dc

Jumper

DOC0506A

Figure 4-5. Analog Input Module Field Wiring

Note

: All I/O modules are isolated on the field side. Be aware that you can

induce ground loops by tying commons from various modules together.



4.4 Analog Output Modules

The 16-bit Analog Output (AO) module has four channels that provide a current output for powering analog devices. Analog Outputs are analog signals the ROC827 generates to regulate equipment, such as control valves or any device requiring analog control.

Each channel on this module provides a 4- to 20-mA current signal for controlling analog current loop devices. The AO module isolation includes the power supply connections.

Note

: AO modules (Part Number W38199) with front labels that read AO-

16 are an earlier version that controls the low side current. AO modules

(Part Number W38269) with front labels that read AO are the newer version (January 2005 and later) and control the high side current.

You can configure the AO module as either 12 or 24 Volts dc via jumper

J4 on the I/O module (see Figure 4-6). The AO module can provide isolated +12 Volts dc or +24 Volts dc field transmitter power on a per module basis. For example, one module can provide +12 Volts dc for powering low-power analog transmitters, while another module in the same ROC827 can provide +24 Volts dc for powering conventional 4- to

20-mA transmitters. Refer to Figure 4-7.

Figure 4-6. Analog Output Jumper J4 (Shown Set to +12V)

+T 12 / 24 V dc

Jumper


Representative

Internal Circuit

CURRENT LOOP

CONTROL

CURRENT LOOP

CONTROL

CURRENT LOOP

CONTROL

CURRENT LOOP

CONTROL


Field Wiring

I +

-

CURRENT LOOP DEVICE 4-20mA

ROC800 POWERED

+V

250

+

-

1-5 VOLT CONTROL DEVICE

DOC0505A

Figure 4-7. Analog Output Module Field Wiring

Note



Issued Mar-06

Caution

The eight-channel Discrete Input (DI) modules monitor the status of relays, open collector/open drain type solid-state switches, and other twostate devices. Discrete Inputs come from relays, switches, and other devices, which generate an on/off, open/close, or high/low signal.

The DI module provides a source voltage for dry relay contacts or for an open-collector solid-state switch.

The DI module’s LEDs light when each input is active.

Each DI channel can be software-configured to function as a momentary or latched DI. A latched DI remains in the active state until reset. Other parameters can invert the field signal and gather statistical information on the number of transitions and the time accumulated in the on- or off-state.

The Discrete Input module operates with non-powered discrete devices, such as “dry” relay contacts or isolated solid-state switches. Use of the DI module with powered devices may cause improper operation or damage.

The DI module senses the current flow, which signals the ROC827 electronics that the relay contacts have closed. The opening of the contacts interrupts the current flow and the DI module signals the ROC827 electronics that the relay contacts have opened. A ROC827 can read a DI a maximum of 20 times per second (50 millisecond scan).


Issued Mar-06

+V

6.6KW


The left side of Figure 4-8 displays the internal circuitry while the right side displays possible field wiring.

Note



DI

1

2

3

4

5

6

7

8

+

-

DRY CONTACT

ROC800 POWERED

+

-

OPEN COLLECTOR

OR

OPEN DRAIN TYPE DEVICE

EXTERNALLY POWERED

8 CHAN

DOC0507A

Figure 4-8. Discrete Input Module Field Wiring

The five-channel Discrete Output (DO) module provides two-state outputs to energize solid-state relays and power small electrical loads. These are solid-state relays. A Discrete Output may be set to send a pulse to a specified device. Discrete Outputs are high and low outputs used to turn equipment on and off.

DO modules can be software-configured as latched, toggled, momentary, or Timed Duration Outputs (TDO). The DO can be configured to either retain the last value on reset or use a user-specified fail-safe value.

The DO module provides LEDs that light when each output is active.

When a request is made to change the state of a DO, the request is immediately sent to the DO module. There is no scan time associated with a DO. Under normal operating conditions, the DO channel registers the change within 2 milliseconds.

If the DO is in momentary or toggle mode, you can enter a minimum timeon of 4 milliseconds.

Figure 4-9 displays the field wiring connections to the output circuit of the

DO module.



Caution

The Discrete Output module only operates with non-powered discrete devices, such as relay coils or solid-state switch inputs. Using the module with powered devices may cause improper operation or damage.

DO modules draw power for the active circuitry from the backplane, and are fused for protection against excessive current.

Note

: When using the Discrete Output module to drive an inductive load

(such as a relay coil), place a suppression diode across the input terminals to the load. This protects the module from the reverse Electro-Motive

Force (EMF) spike generated when the inductive load is switched off.

Representative

Internal Circuit

+V s

CONTROL

DO

+

-

1+

COM

2+

COM

3 +

COM

4 +

COM

5 +

COM

5 CHAN

Field Wiring

-

DISCRETE DEVICE

EXTERNALLY POWERED

+

-

DOC0508A

Figure 4-9. Discrete Output Module Field Wiring

Note: All I/O modules are isolated on the field side. Be aware that you can


4.7 Discrete Output Relay Modules

The five-channel DO Relay (DOR) module provides LEDs that light when each output is active. DOR modules use dual-state latching relays to provide a set of normally open, dry contacts capable of switching 2 A at

32 Volts dc across the complete operating temperature. You can configure the module as latched, toggled, momentary, or Timed Duration Outputs

(TDO). The DOR can either retain the last value on reset or use a userspecified fail-safe value.

Figure 4-10 displays the field wiring connections to the output circuit of the DO Relay module.



Note

: The Discrete Output Relay module operates only with discrete

devices having their own power source.

When a request is made to change the state of a DOR, the request is immediately sent to the DOR module. There is no scan time associated with a DOR. Under normal operating conditions, the DOR channel registers the change within 12 mSecs. If the DOR is in momentary or toggle mode, DOR channels register the change within 48 mSecs.

The DOR modules draw power for the active circuitry from the backplane.

Note

: On power up or reset, the DO Relay module’s LEDs enter

indeterminate state for a few seconds as the module self-identifies. The

LEDs may flash, stay on, or stay off for a few seconds.

Vs

CONTROL

Vs

CONTROL

S R

LATCHING RELAY

NOTE: S = SET

R = RESET

S R

DO -

RELA Y

+

-

+

-

+

-

+

-

+

-

+

-

DISCRETE DEVICE

SELF- POWERED

-

DISCRETE DEVICE

EXTERNALLY POWERED

+

-

5 CHAN

DOC0509A

Figure 4-10. Discrete Output Relay Module Field Wiring

Note



4.8 Pulse Input Modules

The Pulse Input (PI) module provides two channels for measuring either a low speed or high speed pulse signal. The PI module processes signals from pulse-generating devices and provides a calculated rate or an accumulated total over a configured period. Supported functions are slowcounter input, slow rate input, fast counter input, and fast rate input.



Caution

The PI is most commonly used to interface to relays or open collector/open drain type solid-state devices. The Pulse Input can be used to interface to either self-powered or ROC827-powered devices.

The high speed input supports signals up to 12 kHz while the low speed input is used on signals less than 125 Hz.

You can configure the PI module as either 12 or 24 Volts dc using jumper

J4 on the I/O module (see Figure 4-11). The PI modules can provide isolated +12 Volt dc or +24 Volt dc field transmitter power on a permodule basis. For example, one module can provide +12 Volt dc power, while another module in the same ROC827 can provide +24 Volt dc power. Refer to Figures 4-12 and 4-13.

The PI module provides LEDs that light when each input is active.

The Pulse Input module only operates with non-powered devices, such as

“dry” relay contacts or isolated solid-state switches. Use of the PI module with powered devices may cause improper operation or damage.

The PI modules draw power for the active circuitry from the backplane.

Input signals are optically isolated.

Note

: Do not connect wiring to both the Low and High speed selections

for a given channel. This results in unpredictable operation of the PI module.

Issued Mar-06

Figure 4-11. Pulse Input J4 Jumper (Set to +12 V)

+T 12 / 24 V dc

Jumper


Representative

Internal Circuit

12KHz PI FILTER &

LEVEL DETECTION

12KHz PI FILTER &

LEVEL DETECTION


+

-

Field Wiring

OPEN DRAIN TYPE

OR

OPEN COLLECTOR DEVICE

EXTERNALLY POWERED

+

-

CONTACT-CLOSURE DEVICE

EXTERNALLY POWERED

DOC0510A

Figure 4-12. Externally Powered Pulse Input Module Field Wiring

Representative

Internal Circuit

12KHz PI FILTER &

LEVEL DETECTION

PI

L

H

L

H

Field Wiring

+

-

+T

OPEN COLLECTOR

OR

OPEN DRAIN TYPE DEVICE

ROC800 POWERED

+

METER COIL

2 CHAN

DOC0511A

Figure 4-13. ROC800-Powered Pulse Input Module Field Wiring

Note



4.9 RTD Input Modules

The Resistance Temperature Detector (RTD) module monitors the temperature signal from an RTD source. The module can accommodate input from a two-, three-, or four-wire RTD source.

The active element of an RTD probe is a precision, temperature-dependent resistor made from a platinum alloy. The resistor has a predictable positive temperature coefficient, meaning its resistance increases with temperature.



The RTD input module works by supplying a small consistent current to the RTD probe and measuring the voltage drop across it. Based on the voltage curve of the RTD, the ROC827 firmware converts the signal to temperature.

The RTD input module monitors the temperature signal from a resistance temperature detector (RTD) sensor or probe. A two-channel 16-bit RTD module is available. The RTD module isolation includes the power supply connections.

The RTD modules draw power for the active circuitry from lines on the backplane.

It may be more convenient to perform calibration before connecting the field wiring. However, if the field wiring between the ROC827 and the

RTD probe is long enough to add a significant resistance, then perform calibration in a manner that considers this.

4.9.1 Connecting the RTD Wiring

Temperature can be input through the Resistance Temperature Detector

(RTD) probe and circuitry. An RTD temperature probe mounts directly to the piping using a thermowell. Protect RTD wires either by a metal sheath or by conduit connected to a liquid-tight conduit fitting. The RTD wires connect to the four screw terminals designated “RTD” on the RTD module.

The ROC827 provides terminations for a four-wire 100-ohm platinum

RTD with a DIN 43760 curve. The RTD has an alpha equal to 0.00385 or

0.00392

Ω/Ω°C. You can use a two-wire or three-wire RTD probe instead of a four-wire probe, but they may produce measurement errors due to signal loss on the wiring.

Wiring between the RTD probe and the ROC827 must be shielded wire, with the shield grounded only at one end to prevent ground loops. Ground loops cause RTD input signal errors.

Table 4-1. RTD Signal Routing

Signal Terminal Designation

CH 1 (REF) 1 Constant Current +

CH 1 (+)

CH 1 (–)

2

3

V+ RTD

V– RTD

Constant Current – CH 1 (RET)

Not Connected

CH 2 (REF)

CH 2 (+)

CH 2 (–)

CH 2 (RET)

Not Connected

4

5

6

7

8

9

10

Constant Current +

V+ RTD

V– RTD

Constant Current –

N/A

N


4-Wire RTD


Note



3-Wire RTD

2-Wire RTD

Red

Red

Jumper

Red

Jumper

Red

Jumper

Figure 4-14. RTD Sensor Wiring Terminal Connections

Figure 4-14 and Table 4-2 display the connections at the RTD terminals for the various RTD probes.

Table 4-2. RTD Wiring

Terminal 4-Wire RTD

REF Red

+

–

RET

Red

White

White

3-Wire RTD

Jumper to +

2-Wire RTD

Jumper to +

Red, Jumper to REF Red, Jumper to REF

White White, Jumper to RET

White Jumper to –

Note

: The wire colors for the RTD being used may differ.

4.10 J and K Type Thermocouple Input Modules

The five-channel J and K Type Thermocouple Input module monitors either J or K Type Thermocouple (T/C). J and K refer to the type of material used to make a bimetallic junction: Type J (Iron/Constantan) and

Type K (Chromel/Alumel). These dissimilar junctions in the thermocouple junction generate different millivolt levels as a function of the heat to which they are exposed.

The J and K Type Thermocouple Input module measures the voltage of the thermocouple to which it is connected. The T/C voltage is measured and a Cold Junction Compensation (CJC) correction factor is applied to compensate for errors due to any voltage inducted at the wiring terminals


ROC827 Instruction Manual by the junction between the different metal of the T/C wiring and the T/C module’s terminal blocks.

Note

: The use of dissimilar metals is not supported. It will not provide the

correct results, as CJC is applied at the module level.

Caution

Thermocouples are self-powered and require no excitation current. The thermocouple modules use integrated short-circuit protected isolated power supplies and completely isolates the field wiring side of the module from the backplane.

If using the Type J above 750°C (1382°F), abrupt magnetic transformation causes permanent de-calibration of the T/C wires.

De-calibration

De-calibration can occur in thermocouple wires. De-calibration is the process of unintentionally altering the makeup of the thermocouple, usually caused by the diffusion of atmospheric particles into the metal at the extremes of the operating temperature range. Impurities and chemicals can cause de-calibration from the insulation diffusing into the thermocouple wire. If operating at high temperatures, check the specification of the probe insulation. It is advised to use thermocouples with insulated junctions to protect against oxidation and contamination.

Thermocouples use thin wire (typically 32 AWG) to minimize thermal shunting and increase response times. Wire size used in the thermocouple depends upon the application. Typically, when longer life is required for the higher temperatures, select the larger size wires. When sensitivity is the prime concern, use smaller size wiring. Thin wire causes the thermocouple to have a high resistance that can cause errors due to the input impedance of the measuring instrument. If thermocouples with thin leads or long cables are required, keep the thermocouple leads short and use a thermocouple extension wire to run between the thermocouple and measuring instrument.

The thermocouple wires directly to the module’s removable terminal block. No special terminal or isothermal block is required.



+

-

J OR K THERMOCOUPLE

UNGROUNDED SHEATH

Issued Mar-06

DOC0512B

Figure 4-15. Type J and K Thermocouple Wiring

Be sure to use the correct type of thermocouple wire to connect the thermocouple to the ROC827. Minimize connections and make sure connections are tight. If you use any dissimilar metals (such as copper wire) to connect a thermocouple to the ROC827, you can create the junction of dissimilar metals that can generate millivolt signals and increase reading errors.

Ensure any plugs, sockets, or terminal blocks used to connect the extension wire are made from the same metals as the thermocouples and observe correct polarity.

The thermocouple probe must have sufficient length to minimize the effect of conduction of heat from the hot end of the thermocouple. Unless there is insufficient immersion, readings will be low. It is suggested the thermocouple be immersed for a minimum distance equivalent to four times the outside diameter of a protection tube or well.

Use only ungrounded thermocouple constructions. Grounded

thermocouples are susceptible to the creation of ground loops. In turn, ground loops can cause interaction between thermocouple channels on the thermocouple module.

Note

: Use thermocouples as individual sensing devices. All modules are

isolated on the field side. Be aware that you can induce ground loops by tying module-to-module commons together.



Noise Susceptibility

Millivolt signals are very small and are very susceptible to noise.

Noise from stray electrical and magnetic fields can generate voltage signals higher than the millivolt levels generated from a thermocouple. The T/C modules can reject common mode noise

(signals that are the same on both wires), but rejection is not perfect, so minimize noise where possible.

Take care to properly shield thermocouple wiring from noise by separating the thermocouple wiring runs from signals that are switching loads and

AC signals. Route wires away from noisy areas and twist the two insulated leads of the thermocouple cable together to help ensure both wires pickup the same noise. When operating in an extremely noisy environment, use a shielded extension cable.

+

+

TypeJus.dsf

–

TypeKus.dsf

–

Figure 4-16. Type J Thermocouple Shielded

Wiring – United States Color Coding

Figure 4-17. Type K Thermocouple Shielded

Wiring – United States Color Coding

United States color-coding for the Type J Thermocouple shielded wiring is black sheathing, the positive lead is white, and the negative lead is red.

United States color-coding for the Type K Thermocouple shielded wiring is yellow sheathing, the positive lead is yellow, and the negative lead is red.

Caution

Shielded wiring is recommended. Ground shields only on one end, preferably at the end device unless you have an excellent ground system installed at the ROC800-series controller. Do not tie the thermocouple module to ground.

Note

: It is highly recommended that you use shielded wiring.

Sheathed thermocouple probes are available with one of three junction types: grounded, ungrounded, or exposed. unground.dsf

ground.dsf

exposed.dsf

Figure 4-18. Ungrounded –

Sheathed

Figure 4-19. Grounded

Figure 4-20. Exposed,

Ungrounded – Unsheathed

In an ungrounded probe, the thermocouple junction is detached from the probe wall. Response time slows down from the grounded style, but the ungrounded probe offers electrical isolation of 1.5 M ½ at 500 Volts dc in all diameters. The wiring may or may not be sheathed.



Note

: Only ungrounded probes are supported. It is highly recommended

that you use sheathed probes.

Use an ungrounded junction for measurements in corrosive environments where it is desirable to have the thermocouple electronically isolated from and shielded by the sheath. The welded wire thermocouple is physically insulated from the thermocouple sheath by MgO powder (soft).

At the tip of a grounded junction probe, the thermocouple wires physically attach to the inside of the probe wall. This results in good heat transfer from the outside, through the probe wall to the thermocouple junction. Grounded wiring is not supported.

The thermocouple in the exposed junction protrudes out of the tip of the sheath and is exposed to the surrounding environment. This type offers the best response time, but is limited in use to non-corrosive and nonpressurized applications. Exposed junction thermocouples are not

supported.

Note

: Avoid subjecting the thermocouple connections and measurement

instrument to sudden changes in temperature.



4.11 Related Specification Sheets

Refer to the following specification sheets (available at www.EmersonProcess.com/flow ) for additional and most-current information on each of the I/O modules.

Table 4-3. I/O Module Specification Sheets

Name

AI and AO Modules (ROC800-Series)

DI and PI Modules (ROC800-Series)

DO and DOR Modules (ROC800-Series)

RTD and T/C Modules (ROC800-Series)

Form Number

6.3:IOM1

6.3:IOM2

6.3:IOM3

6.3:IOM4

Part Number

D301163X012

D301175X012

D301181X012

D301182X012





Chapter 5 – Communications

This section describes the built-in communications and the optional communication modules used with the ROC827.

In This Chapter

5.1 Communications Ports and Modules Overview.......................................5-1

5.3 Removing a Communications Module.....................................................5-4

5.5 Local Operator Interface (LOI).................................................................5-5

5.5.1 Using the LOI .................................................................................5-7

5.7 EIA-232 (RS-232) Serial Communications ..............................................5-9

5.8.1 EIA-422/485 (RS-422/485) Jumpers & Termination Resistors....5-11

5.9 Dial-up Modem Communications Module..............................................5-12

5.1 Communications Ports and Modules Overview

The built-in communications and the optional communication modules provide communications between the ROC827 and a host system or external devices.

The ROC827 allows up to six communication ports. Three communication ports are built-in on the CPU. You can add up to three additional ports with communication modules. Table 5-1 displays the types of communications available for the ROC827.

Table 5-1. Built-in Communications and Optional Communication Modules

Communications

EIA-232 (RS-232D) Local Operator Interface (LOI)

Ethernet (use with DS800 Configuration Software)

EIA-232 (RS-232C) Serial Communications

EIA-422/485 (RS-422/485) Serial Communications

Modem Communications

MVS Sensor Interface

Built-in on CPU

Local Port

Comm1

Comm2

Optional Module

Comm3 to Comm5

Comm3 to Comm5

Comm3 to Comm5

Comm3 to Comm5

The communication modules consist of a communications module (card), a communications port, wiring terminal block, LEDs, and connectors to the backplane. The ROC827 unit can hold up to three communication modules in the first three module slots. Refer to Figure 5-1.

Issued Mar-06 Communications 5-1


Optional Comm 3

(Slot #1)

LOI (Local Port)

EIA-232 (RS-232D)

Optional Comm 3 or Comm 4

(Slot #2)

Built-in Ethernet (Comm1)

Optional Comm 3 to Comm 5

(Slot #3)

Built-in EIA-232

(RS-232) (Comm2)

Figure 5-1. Communication Ports

Table 5-2. Communication LED Indicator Definitions

Signals Action

CTS Clear To Send indicates the modem is ready to send.

CD Data Carrier Detect (DCD) indicates a valid carrier signal tone detected.

DSR Data Set Ready for ring indicator communication signal.

DTR Data Terminal Ready to answer an incoming call. When off, a connection disconnects.

RTS Ready To Send indicates ready to transmit.

RX

TX

Receive Data (RD) signal is being received.

Transmit Data (TD) signal is being transmitted.

Each communications module has surge protection in accordance with the

CE certification EN 61000. Each communications module is completely isolated from other modules and the backplane, including power and signal isolation, with the exception of the EIA-232 (RS-232) module. The field interface has been designed to protect the electronics in the module.

Filtering is provided on each module to reduce communication errors.



5.2 Installing Communication Modules

All communication modules install into the ROC827 in the same way.

You can install or remove communication modules while the ROC827 is powered up (hot-swappable), you can install modules directly into unused module slots 1, 2, or 3 (hot-pluggable), and modules are self-identifying in the software. All modules are self-resetting after a fault clears.

Note

: The dial-up modem module is not hot-swappable or hot-pluggable.

When you install a dial-up modem module, you must remove power from the ROC827.

Issued Mar-06

Figure 5-2. Example RS-485 Communications Module

Caution


Note

: You can install communications modules only in slots 1, 2, or 3 of

the ROC827. Refer to Figure 5-1.

1.


Note

: Leaving the wire channel cover in play can prevent the module

from correctly connecting to the socket on the backplane.

2.

Perform one of the following:

Communications 5-3


If there is a module currently in the slot, unscrew the captive screws and remove that module (refer to “Removing a

Communications Module”).

If the slot is currently empty, remove the module cover.

3.

Insert the new module through the module slot on the front of the

ROC827 housing. Make sure the label on the front of the module is facing right side up. Gently slide the module in place until it contacts properly with the connectors on the backplane.

Note

: If the module stops and will not go any further, do not force the

module. Remove the module and see if the pins are bent. If so, gently straighten the pins and re-insert the module. The back of the module

must connect fully with the connectors on the backplane.

4.

Gently press the module into its mating connectors on the backplane until the connectors firmly seat.

5.

Install the retaining captive screws to secure the module.

6.

Wire the module (refer to “Wiring Communications Modules”).

Note

: All modules have removable terminal blocks for convenient

wiring and servicing. Twisted-pair cable is recommended for I/O signal wiring. The removable terminal blocks accept 12 AWG or smaller wire.

7.

For dial-up modem communications, connect the cable to the RJ-11 connector on the communications module.

Note

: If you are installing a modem module, it is recommended that

you install a surge protector between the RJ-11 jack and the outside line.

8.


9.

Connect to ROCLINK 800 software and login. The modules are selfidentifying after re-connecting to ROCLINK 800 software.

5.3 Removing a Communications Module

To remove a communications module:

1.


2.

Unscrew the two captive screws holding the module in place.

3.

Gently pull the module’s lip out and remove the module from the slot.

You may need to gently wiggle the module.

4.

Install a new module or install the module cover.

5.

Screw the two captive screws to hold the module in place.



6.


5.4 Wiring Communications Modules

Caution

Signal wiring connections to the communications are made through the communications port removable terminal bock connectors and through RJ-

11 and RJ-45 connectors. All modules have removable terminal blocks for convenient wiring and servicing. The terminal blocks can accommodate a wide range of wire gauges (12 AWG or smaller).



1.


2.


3.

Tighten the screw.


Note

: All modules have removable terminal blocks for convenient wiring

and servicing. Twisted-pair cable is recommended for I/O signal wiring.

The removable terminal blocks accept 12 AWG or smaller wire.

5.5 Local Operator Interface (LOI)

The Local Operator Interface (LOI) local port provides direct communications between the ROC827 and the serial port of an operator interface device, such as an IBM compatible computer. The interface allows you to access the ROC827 with a direct connection using

ROCLINK 800 software to configure and transfer stored data.

The LOI uses the Local Port in ROCLINK 800 software.

The LOI terminal (RJ-45) on the CPU provides wiring access to a built-in

EIA-232 (RS-232) serial interface, which is capable of 57.6K baud operation. The RJ-45 connector pin uses the data terminal equipment

(DTE) in the IEEE standard.

The LOI port supports ROC Plus and Modbus protocol communications.

The LOI also supports the log-on security feature of the ROC827 if you have enabled the Security on LOI in the ROCLINK 800 software.

Table 5-3 shows the signal routing of the CPU connections. Figure 5-3 shows the RJ-45 pin out.



DTR

GND

RX

TX

RTS

Table 5-3. Built-in LOI EIA-232 Signal Routing

RJ-45 Pins

Function on ROC827

Data Terminal

Ready

Ground

(Common)

Receive

Transmit

Request to Send

3

4

5

6

8

Description

Originated by the ROC827 Data Terminal Equipment (DTE) to instruct the Data Communication Equipment (DCE) to setup a connection.

DTE is running and ready to communicate.

Reference ground between a DTE and a DCE and has a value 0 Volts dc.

Data received by the DTE.

Data sent by the DTE.

Originated by the DTE to initiate transmission by the DCE.

Figure 5-3. RJ-45 Pin Out

The LOI terminal requires the installation of a D-Sub 9 pin (F) to RJ-45 modular converter between the ROC827 and personal computer (PC).

Refer to Table 5-4.

Table 5-4. RJ-45 to EIA-232 (RS-232) Null-modem Cable Signal Routing

EIA-232

(RS-232)

DTE

ROC800-

Series

RJ-45 Pins on ROC800-

Series

4 – 1

1 – 2

7 – 7

Table 5-5. Using Cable Warehouse 0378-2 D-Sub to Modular Converter 9-Pin to RJ-45 Black

Pin

Wire

Color

1 Blue


Series

4

2 Orange 1

3 Black 6



Pin

Wire

Color

4 Red


Series

5

5 Green 3

6 Yellow

7 Brown

8 Gray

2

7

8

5.5.1 Using the LOI

1.

Plug the LOI cable into the LOI RJ-45 connector of the ROC827.

2.

Connect the LOI cable to the D-Sub 9 pin (F) to RJ-45 modular converter.

3.

Plug the modular converter into the COM Port of the personal computer.

4.

Launch ROCLINK 800 software.

5.

Click the Direct Connect icon.

6.

Configure communications for the other built-in and modular communications, I/O modules, AGA meter parameters, and other configuration parameters.

Issued Mar-06

The Ethernet communications port in the ROC827 allows TCP/IP protocol communications using the IEEE 802.3 10Base-T standard. One application of this communications port is to download programs from

DS800 Development Suite Configuration Software.

The Ethernet communications port uses a 10BASE-T Ethernet interface with an RJ-45 connector. Each Ethernet-equipped unit is called a station and operates independently of all other stations on the network without a central controller. All attached stations connect to a shared media system.

Signals are broadcast over the medium to every attached station. To send an Ethernet packet, a station listens to the medium (Carrier Sense) and when the medium is idle, the station transmits the data. Each station has an equal chance to transmit (Multiple Access).

Access to the shared medium is determined by the Medium Access

Control (MAC) mechanism embedded in each station interface. The MAC mechanism is based on Carrier Sense Multiple Access with Collision

Detection (CSMA/CD). If two stations begin to transmit a packet at the same instant, the stations stop transmitting (Collision Detection).

Transmission is rescheduled at a random time interval to avoid the collision.

Communications 5-7

Issued Mar-06


You can link Ethernet networks together to form extended networks using bridges and routers.

Table 5-6. Ethernet Signal LEDs

Signal Function

RX Lit when currently receiving.

TX

COL

LNK

Lit when currently transmitting.

Lit when Ethernet Packet Collision detected.

Lit when Ethernet has linked.

Use a rugged industrial temperature HUB when connecting Ethernet wiring in an environment that requires it.

The IEEE 802.3 10BASE-T standard requires that 10BASE-T transceivers be able to transmit over a link using voice grade twisted-pair telephone wiring that meets EIA/TIA Category four wire specifications. Generally, links up to 100 meters (328 feet) long can be achieved for unshielded twisted-pair cable.

For each connector or patch panel in the link, subtract 12 meters (39.4 feet) from the 100-meter limit. This allows for links of up to 88 meters

(288 feet) using standard 24 AWG UTP (Unshielded Twisted-Pair) wire and two patch panels within the link. Higher quality, low attenuation cables may be required when using links greater than 88 meters.

The maximum insertion loss allowed for a 10BASE-T link is 11.5 dB at all frequencies between 5.0 and 10.0 MHz. This includes the attenuation of the cables, connectors, patch panels, and reflection losses due to impedance mismatches to the link segment.

Intersymbol interference and reflections can cause jitter in the bit cell timing, resulting in data errors. A 10BASE-T link must not generate more than 5.0 nanoseconds of jitter. If your cable meets the impedance requirements for a 10BASE-T link, jitter should not be a concern.

The maximum propagation delay of a 10BASE-T link segment must not exceed 1000 nanoseconds.

Crosstalk is caused by signal coupling between the different cable pairs contained within a multi-pair cable bundle. 10BASE-T transceivers are designed so that you do not need to be concerned about cable crosstalk, provided the cable meets all other requirements.

Noise can be caused by crosstalk of externally induced impulses. Impulse noise may cause data errors if the impulses occur at very specific times during data transmission. Generally, do not be concerned about noise. If you suspect noise related data errors, it may be necessary to either reroute the cable or eliminate the source of the impulse noise.

Multi-pair, PVC 24 AWG telephone cables have an attenuation of approximately 8 to 10 dB/100 m at 200°C (392°F). The attenuation of

PVC insulted cable varies significantly with temperature. At temperatures

Communications 5-8

ROC827 Instruction Manual greater than 400°C (752°F), use plenum rated cables to ensure that cable attenuation remains within specification.

When connecting two twisted-pair Medium Attachment Units (MAUs) or repeaters together over a segment, wire the transmit data pins of one eightpin connector to the receive data pins of the other connector, and vice versa. There are two methods for accomplishing 10BASE-T crossover wiring:

Using special cable.

Wiring the 10BASE-T crossover inside the hub.

For a single segment connecting only two devices, provide the signal crossover by building a special crossover cable, wire the transmit data pins of one eight-pin connector to the receive data pins of the other connector, and vice versa. Refer to Figure 5-4.

Signal Signal

Pin 1 TD+

Pin 2 TD–

Pin 3 RD+

Pin 6 RD–

Pin 1 TD+

Pin 2 TD–

Pin 3 RD+

Pin 6 RD–

Figure 5-4. 10BASE-T Crossover Cable

5.7 EIA-232 (RS-232) Serial Communications

The built-in EIA-232 (RS-232), the LOI, and the communication modules meet all EIA-232 (RS-232) specifications for single-ended, asynchronous data transmission over distances of up to 15 meters (50 feet). EIA-232

(RS-232) communication provides transmit, receive, and modem control signals. The LOI port also meets EIA-232D (RS-232D) specifications.

The EIA-232 (RS-232) communications have the following communication port designations in ROCLINK 800.

LOI – Local Port EIA-232 (RS-232D). Refer to Section 5.5, “Local

Operator Interface.”.

Built-in – Comm2 EIA-232 (RS-232C).

Module – Comm3 to Comm5 EIA-232 (RS-232C).

EIA-232 (RS-232) uses point-to-point asynchronous serial communications and is commonly used to provide the physical interface for connecting serial devices, such as gas chromatographs and radios to the ROC800-Series. The EIA-232 (RS-232) communication provides essential hand-shaking lines required for radio communications, such as

DTR and RTS.



The EIA-232 (RS-232) communications includes LED indicators that display the status of the Receive (RX), Transmit (TX), Data Terminal

Ready (DTR), and Ready To Send (RTS) control lines.

Table 5-7 defines the built-in EIA-232 (RS-232) terminals at the Comm2 port and their function signals.

Table 5-7. Built-in EIA-232 (RS-232) Signal Routing – Comm2

RX

TX

Lit when Comm2 is currently receiving.

Lit when Comm2 is currently transmitting.

RTS Lit when Comm2 ready to send is not active.

DTR Lit when Comm2 data terminal ready is active.

GND Common.

1

2

3

4

5

The EIA-232 (RS-232) communications module provides for EIA-232

(RS-232C) signals on the Comm3, Comm4, or Comm5 port depending on where the module is installed. Refer to Table 5-8.

Table 5-8. EIA-232 (RS-232) Communication Module Signal Routing – Comm3, Comm4, and Comm5

RX Lit when module (Comm3, Comm4, or Comm5) is currently receiving.

TX Lit when module (Comm3, Comm4, or Comm5) is currently transmitting.

RTS Lit when module (Comm3, Comm4, or Comm5) is ready to send is not active.

DTR Lit when module (Comm3, Comm4, or Comm5) data terminal ready is active.

GND Common.

1

2

3

4

5

5.8 EIA-422/485 (RS-422/485) Serial Communications Module

EIA-422/485 (RS-422/485) communication modules meet all EIA-

422/485 (RS-422/485) specifications for differential, asynchronous serial communication transmissions of data over distances of up to 1220 meters

(4000 feet). EIA-485 (RS-485) communications are commonly used to multi-drop units on a serial network over long distances using inexpensive twisted-pair wiring.

EIA-422 (RS-422) drivers are designed for party-line applications where one driver is connected to, and transmits on, a bus with up to ten receivers.

EIA-422 (RS-422) allows long distance point-to-point communications and the drivers are designed for true multi-point applications with up to 32 drivers and 32 receivers on a single bus.

The default values for the EIA-422/485 (RS-422/485) communications are

19200 Baud Rate, 8 Data Bits, 1 Stop Bit, and No Parity. The maximum rate is 57.6K bps.



EIA-422/485 (RS-422/485) communication modules include LED indicators that display the status of receive and transmit activity. Refer to

Tables 5-9 and 5-10.

Table 5-9. EIA-422 (RS-422) Signal Routing – Comm3, Comm4, and Comm5

Signal RS-422

A RX +

Function

Lit when module (Comm3, Comm4, or Comm5) is currently receiving.

Y TX + Lit when module (Comm3, Comm4, or Comm5) is currently transmitting.

Terminal

1

2

3

4

5

Table 5-10. EIA-485 (RS-485) Signal Routing – Comm3, Comm4, and Comm5

Signal RS-485

A RX / TX +

Function

Lit when module (Comm3, Comm4, or Comm5) is currently receiving.

B RX / TX – Lit when module (Comm3, Comm4, or Comm5) is currently transmitting.

Terminal

1

2

3

4

5

Note

: The EIA-422/485 (RS-422/485) modules are isolated on the field

side. Be aware that you can induce ground loops by tying commons together.

EIA-422/485 (RS-422/485) communications provides EIA-422/485 (RS-

422/485) signals on the Comm3, Comm4, or Comm5 port, depending on where the module is installed. Wiring should be twisted-pair cable, one pair for transmitting, and one pair for receiving. The EIA-422 (RS-422) module uses four wires and the EIA-485 (RS-485) uses two wires for connectivity.

5.8.1 EIA-422/485 (RS-422/485) Jumpers & Termination Resistors

Four jumpers—J3, J4, J5, and J6—are located on the EIA-422/485 (RS-

422/485) communications module. These jumpers determine the mode in which the module runs (RS-422 or RS-485) and if the module is terminated.

Terminations are required on the two EIA-422/485 (RS-422/485) communication modules located at the extremities of the circuit. That is to say, the two outside modules require terminations in order to complete the communications circuit.



Figure 5-5. EIA-422/485 (RS-422/485) J4 Jumper

Table 5-11. EIA-422 (RS-422) Module

Jumper

TER Out Half Full TER Out Half Full

J3 x x

J4 x x

J5 x x

J6 x x

Table 5-12. EIA-485 (RS-485) Module

Jumper

TER OUT Half Full TER OUT Half Full

J3 x x

J4 x x

J5 x x

J6 x x

5.9 Dial-up Modem Communications Module

The dial-up modem module interfaces to a Public-Switched Telephone

Network (PSTN) line, and requires a telephone line connection. The module provides a telephone interface on the host port that is capable of both answering and originating telephone calls. The module also provides electronics that conserve power when the phone line is not in use.



Note

: When installing a dial-up modem module, you must remove power

from the ROC827.

The dial-up modem provides communications with speeds up to 14.4K bps with V.42 bis and V.42, MNP2-4 and MNP10 error correction, and is

FCC Part 68 approved for use with PSTNs. The FCC label on the module provides the FCC registration number and the ringer equivalent. The module supports data compression, error correction, and nonvolatile RAM for permanent storage of the modem configuration.

Using asynchronous operation, the module interfaces to two-wire, fullduplex telephone lines. It interfaces to a PSTN through an RJ-11 jack.

You control the modem using industry-standard AT command software. A

40-character command line is provided for the AT command set, which is compatible with EIA document TR302.2/88-08006.

The dial-up modem automatically hangs up after a user-configured period of communications inactivity and provides automated dial-up alarm reporting capabilities. Refer to the ROCLINK 800 Configuration Software

User Manual (Form A6121).

Table 5-13. RJ-11 Field Connections

Signal Pin

Tip 3

Ring 4

LED indicators on the module show the status of the Receive (RX),

Transmit (TX), Ring (RI), and Carrier Detect (CD) control lines.

Table 5-14 displays connector signals and their functions.

Table 5-14. Modem Signal Routing – Comm3, Comm4, and Comm5

Signal Function Terminal

RX Lit when module (Comm3, Comm4, or Comm5) is currently receiving. 1

TX

RI

CD

Lit when module (Comm3, Comm4, or Comm5) is currently transmitting (Tip).

Lit when module (Comm3, Comm4, or Comm5) on ring (Ring).

Lit when module (Comm3, Comm4, or Comm5) on carrier detect.

3

7

9

Notes

:

If you are installing a modem module, it is recommended that you install a surge protector between the RJ-11 jack and the outside line.

The dial-up modem is not hot-swappable or hot-pluggable. When installing a dial-up modem module, you must remove power from the

ROC827.



5.10 Multi-Variable Sensor (MVS) Interface Modules

The Multi-Variable Sensor (MVS) provides differential pressure, static pressure, and temperature inputs to the ROC827 unit for orifice flow calculation.

The MVS module consists of interface electronics that provide the communications link between the ROC827 and the MVS. The interface electronics controls communications with the sensor module, provides scaling of process variables, aids calibration, stores operating parameters, performs protocol conversion, and responds to requests from the ROC827.

The ROC827 handles up to two MVS interface modules. Each MVS module provides the communications interface and the isolated, shortcircuit current-limited power required to connect up to six MVS sensors.

The MVS modules create six points automatically for each of the six possible MVS channels. The points include 1 through 6 and if you have a second MVS module installed, points 7 through 12 are available. Points are assigned based on which module is in the first slot. For example, if an

MVS module is in slot three, it automatically assigns the points 1 through

6. If you then install an MVS module into slot one, the points are reassigned so that slot one holds points 1 through 6 and slot three holds points 7 through 12.

The ROC827 allows six MVS devices to be connected on its communications bus in a multi-drop connection scheme. You must set the address of each MVS prior to final wiring of multiple MVS devices. For proper operation of multiple MVS devices, each MVS device must have a unique address. None of the addresses can be 240. For details on MVS configuration, refer to the ROCLINK 800 Configuration Software User

Manual (Form A6121).

Once you set a unique address for each MVS, connect the MVS units in a multi-drop arrangement. The only requirement for wiring multi-drop devices is that all like terminals be tied together. This means all the “A” terminals on the devices are electrically connected to the ROC827’s “A” terminal and so on. To do this, daisy-chain wire each remote MVS.

Terminations are required on the two MVS modules located at the extremities of the circuit. That is to say, the two outside modules require terminations in order to complete the communications circuit. The MVS termination jumper is located at J4 on the module. Refer to Table 5-15 and

Figure 5-6.

Table 5-15. MVS Termination

Jumper

TER OUT TER OUT

J4 x x



Issued Mar-06

Figure 5-6. MVS Jumper J4 (Shown Not Terminated)

Four wires run from the MVS module terminal block and connect to the sensor. The wires should be a minimum size of 22 AWG and a maximum length of 1220 m (4000 ft).

Note

: Insulated, shielded, twisted-pair wiring is required when using MVS

signal lines.

Two of the terminal blocks provide power and the other two terminals provide a communication path. Table 5-16 identifies the terminals.

Table 5-16. MVS Signal Routing – Comm3, Comm4, and Comm5

Label MVS

A RX / TX +

LED

Lit green when receiving

B RX / TX –

None No Connect

N/A

Lit green when transmitting

– Common

N/A

N/A

Terminal

1

2

3

4

5

Notes

:

Pay close attention to the connections; do not reverse the power

wires. Make these connections only after removing power from the

ROC827. Double-check connections for the proper orientation before applying power. If the connections are reversed and power is applied, you will damage both the MVS module and the ROC800-Series processor board.

Communications 5-15


MVS modules are isolated on the field side. Be aware that you can induce ground loops by tying commons together.

5.11 HART Interface Module

The HART

®

Interface module allows a ROC827 to communicate with

HART devices using the Highway Addressable Remote Transducer

(HART) protocol. The HART module can receive signals from HART transmitters or receive and transmit signals from HART transducers. LEDs provide a visual indication of the status of each HART channel. Refer to

Figure 4-21.

Note

: The ROC827 currently supports the HART module only when

installed in slot 1, 2, or 3 of the ROC827 base unit.

The HART module has four analog channels. When configured as an input, you can configure the channel for use in point-to-point or multidrop mode and typically connects to some type of transmitter, such as for a temperature reading. When configured as an output, you can configure the channel for use in point-to-point mode only. The output supports a

Digital Valve Controller (DVC).

Point-to-Point Mode

In point-to-point mode, digital communications are superimposed using the Frequency Shift Keying (FSK) technique on the 4 to 20 milliAmp analog signal (which can still measure the process variable).

This mode allows communications with one HART device per analog channel.

Multi-drop Mode

In multi-drop mode, you can connect up to five HART devices (in parallel) to each analog input channel. As with the point-to-point mode, digital communications are superimposed on the 4 to 20 milliAmp signal. However, the analog signal is used only to measure the current consumed by the multi-drop loop. When all four analog inputs are in the multi-drop mode, the ROC827 can support a maximum of 20 HART devices. The number of devices per channel is limited by the static current draw of the devices.

A ROC827 equipped with a HART module is considered to be a HART

Host (primary master) interface with a Class 1 Conformance classification.

Most Universal and some Common Practice commands are supported. For a list of the commands, refer to the HART Communication Module specification sheet (6.3:HART). The supported commands conform to

HART Universal Command Specification Revision 5.1 and Common

Practice Command Specification Revision 7, (HCF SPEC 127 and 151).

Refer to www.hartcomm.org for more information on the specifications.

The HART module polls the channels simultaneously. If more than one device is connected to a channel in a multi-drop configuration, the module polls one device per channel at a time. The HART protocol allows one


ROC827 Instruction Manual second per poll for each device, so with five devices per channel the maximum poll time for the channel would be five seconds.

Note

: The ROC827 does not support HART devices configured in Burst

mode (in which the device sends information without a prior request). If you have a HART device configured in Burst mode, use a hand-held Field

Communicator to turn off Burst mode before you connect the device to the ROC827.

The HART module provides “loop source” power (+T) and four channels

(1+ through 4+) for communications. The +T power is current-limited.

When powered by the ROC827, terminal +T is connected in parallel to the positive (+) terminal on all of the HART devices, regardless of the channel to which they are connected. Channel 1+ is wired to the negative (–) terminal of a single HART device, or in parallel to the negative terminals of the devices. Likewise, channel 2+ is wired to the negative (–) terminal of a single HART device, or in parallel to the negative terminals of a second group of HART devices.

When powered by an external device, the positive (+) terminal from the power source is connected in parallel to the positive (+) terminal on all of the HART devices, regardless of the channel to which they are connected.

Channel 1+ on the HART module is wired to the positive (+) terminal of the HART device. The power source negative (–) terminal is connected to the channel’s COM terminal and to the negative (–) terminal of a single

HART device, or in parallel to the negative terminals of the HART devices.

Switches on the module board allow channel-by-channel selection as an

Analog Input (IN) or Analog Output (OUT). The switches for Channel 2 and 4 are located on the front of the module, while the switches for channel 1 and 3 are located on the back of the module. Use a pin to move the switches to the desired state (refer to Figures 5-8 and 5-9).

Note

: Always set the IN or OUT switches before wiring the switch or

applying power.


Representative

Internal Circuit


Field Wiring

Figure 5-7. HART Interface Module Field Wiring

CH3 I/O Switch

Figure 5-8. HART Channels 1 and 3 (back side of board)

CH1 I/O Switch



CH2 I/O Switch

Figure 5-9. HART Channels 2 and 4 (front side of board)

CH4 I/O Switch


ROC827 Remote Operations Controller

3.1.2 24-Volt DC Power Input Module (PM-24)

3.1.3 Auxiliary Output (AUX+ and AUX–)

Removing the

Auxiliary Output Fuse

Installing the Auxiliary

Output Fuse

3.2 Determining Power Consumption

General Calculation

Process

3.2.1 Tuning the Configuration

Tuning Hints

Duty Cycle

Duty Cycle

Duty Cycle

Duty Cycle

Duty Cycle

Duty Cycle

Note: For an MVS sensor, the typical mW per MVS is about 300 mW.

Duty Cycle

Duty Cycle

Duty Cycle

3.3 Removing a Power Input Module

: If you intend to store the ROC827 for an extended period, also

3.4 Installing a Power Input Module

: Remove the plastic module cover and wire channel cover, if

3.5 Connecting the ROC827 to Wiring

3.5.1 Wiring the DC Power Input Module

3.5.2 Wiring the External Batteries

Battery Reserve

: Refer to Table 3-2 concerning LEDs.

3.5.3 Replacing the Internal Battery

Note: Removing the battery erases the contents of the ROC827’s

3.6 Related Specification Sheets

Chapter 4 – Input/Output Modules

4.1 I/O Module Overview

: Figure 4-2 represents a ROC827 with one EXP.

4.2 Installation

: After you install a new I/O module or replace an existing I/O

4.2.1 Installing an I/O Module

: Leaving the wire channel cover in place can prevent the module

: If the module stops and will not go any further, do not force the

4.2.2 Removing an I/O Module

4.2.3 Wiring I/O Modules

: All modules have removable terminal blocks for convenient wiring

4.3 Analog Input Modules

: All I/O modules are isolated on the field side. Be aware that you can

4.4 Analog Output Modules

: All I/O modules are isolated on the field side. Be aware that you can

: All I/O modules are isolated on the field side. Be aware that you can

: When using the Discrete Output module to drive an inductive load

Note: All I/O modules are isolated on the field side. Be aware that you can

4.7 Discrete Output Relay Modules

: The Discrete Output Relay module operates only with discrete

: On power up or reset, the DO Relay module’s LEDs enter

: All I/O modules are isolated on the field side. Be aware that you can

4.8 Pulse Input Modules

: Do not connect wiring to both the Low and High speed selections

: All I/O modules are isolated on the field side. Be aware that you can

4.9 RTD Input Modules

4.9.1 Connecting the RTD Wiring

: All I/O modules are isolated on the field side. Be aware that you can

: The wire colors for the RTD being used may differ.

4.10 J and K Type Thermocouple Input Modules

: The use of dissimilar metals is not supported. It will not provide the

De-calibration

Use only ungrounded thermocouple constructions. Grounded

: Use thermocouples as individual sensing devices. All modules are

Noise Susceptibility

: It is highly recommended that you use shielded wiring.

: Only ungrounded probes are supported. It is highly recommended

supported.

: Avoid subjecting the thermocouple connections and measurement

4.11 Related Specification Sheets

Chapter 5 – Communications

5.1 Communications Ports and Modules Overview

5.2 Installing Communication Modules

: The dial-up modem module is not hot-swappable or hot-pluggable.

: You can install communications modules only in slots 1, 2, or 3 of

: Leaving the wire channel cover in play can prevent the module