Emerson OpenComms-485 User manual

1.
LIEBERT MONITORING GROUP
OpenComms
Network Interface Card
INSTALLATION &
USER MANUAL
Note To Our Valued Customer
To help us better serve you, please contact us
with any comments you have about this manual
or product in general.
We encourage you to comment and would
appreciate your assistance in improving Liebert
products.
Liebert Monitoring Group Applications
Engineering (U.S.)
upstech@liebert.com
Steven Ziejewski – Product Manager
Table of Contents
Section 1: INTRODUCTION ...............................................................6
Specifications.....................................................................................7
Section 2: INSTALLATION ................................................................8
Retrofit Installation ............................................................................8
Environmental Installation.............................................................8
NPower Installation .....................................................................15
User Connections for Opencomms NIC ..........................................17
Section 3: SYSTEM CONFIGURATION ..........................................18
DIP Switch Settings .........................................................................18
Service Terminal..............................................................................18
1. System Information Menu ......................................................20
2. Network Interface Menu .........................................................20
3. SNMP Communications Menu ...............................................21
4. Web Server .............................................................................21
5. Firmware Update Menu ..........................................................22
6. Factory Settings Menu ............................................................22
7. Auxiliary Communications ......................................................22
Section 4: OPERATION.....................................................................23
SNMP ..............................................................................................23
Liebert Global Products MIB.......................................................23
RFC 1628 UPS MIB ....................................................................24
MIB..............................................................................................24
HTTP ...............................................................................................25
Modbus RTU ...................................................................................26
System Reset....................................................................................26
Diagnostics.......................................................................................26
Section 5: MODBUS COMMUNICATIONS & CONNECTIVITY..28
Implementation Basics.....................................................................28
Constraints .......................................................................................28
Transmission Format .......................................................................29
Physical Connection.........................................................................29
Modbus Slave Functions..................................................................31
Data Type ...................................................................................31
Function Code Support.............................................................32
Read/Write Holding Registers (0x03, 0x06, 0x10) ..............32
Read Input Registers (0x04) ....................................................32
Read, Set Coil Status (0x01, 0x05, 0x0F) .............................33
Read Input Status (0x02)..........................................................33
Error Handling ...........................................................................33
Modbus Packet Formats...............................................................34
Read registers (Function Code 0x03 & 0x04)..................................36
Write single holding register (Function Code 0x06)........................36
Section 6: NIC Setup and Testing.......................................................37
Jumper Placements...........................................................................37
Testing the Network.........................................................................37
Service Terminal Troubleshooting...................................................38
SNMP Troubleshooting ...................................................................38
Web Troubleshooting.......................................................................39
Modbus Troubleshooting .................................................................39
Internet Web
Browser
Network Management
System
Ethernet
OpenComms
NIC
Modbus EIA-485
Building Management
System
Figure 1. Typical Installation
Section 1: INTRODUCTION
The Liebert OpenComms Network Interface Card provides
multiple connectivity options for your Liebert equipment.
The OpenComms Network card transforms Liebert units to
intelligent managed nodes on your network, enabling in-band
communications with network management systems (NMS). For
the first time, the system that monitors the well-being of your
computing/communication infrastructure can comprehensively
monitor your Liebert equipment as well.
The OpenComms Network card can also easily integrate to your
existing Building Management or out-of-band monitoring system
using a standard, well-defined multi-drop protocol.
The OpenComms family of interface cards communicates with
external systems via the following industry-standard open
protocols:
•
•
•
Modbus RTU over EIA-485
SNMP v1
HTTP v1.1
The OpenComms Network card is designed to provide redundant
paths for communications. This implies that it is possible to
connect to your existing BMS system using Modbus while
simultaneously communicating to your NMS through SNMP and
HTTP.
Additionally, these protocols allow simple integration into the
network and building management systems, thus leveraging prior
investment and established procedures. Even without an
installed monitoring system, Liebert units may be monitored
“on-demand” via a web browser, from anywhere network access
is permitted.
6
Installation
SPECIFICATIONS
Electrical Requirements:
Voltage: 18VAC to 24VAC
50/60 Hz, Single Phase
12VDC to 36VDC
Power:
6VA maximum
Environmental Conditions:
Operating Ambient Temperature: 5°C to 40°C
41°F to 104°F
Storage Ambient Temperature: -20°C to 60°C
-4°F to 140°F
Relative Humidity:
10% to 90% RH
(Non-condensing)
Dimensions:
Net:
178mm x 102mm x 38mm
7.0” x 4.0” x 1.5”
As shipped:
178mm x 64mm
9.75” x 7.0” x 2.5"
0.2kg
0.4lbs
248mm
0.6kg
1.3lbs
Environmental Compatibility:
Advanced Microprocessor / Graphics
Standard Microprocessor
MiniMate2 (1.5 – 5 ton & 8 ton)
Level 10
Level 00 / 05
3-Phase UPS Compatibility:
NPower
7200 Series
Installation
7
x
Section 2: INSTALLATION
The OpenComms NIC card may be ordered as a factory installed
option, or in a kit for field retrofit to existing Liebert units or as a
self-contained unit in its own enclosure.
If ordered as a factory-installed option, proceed directly to
subsection on User Connections.
As a retrofit kit, the circuit board is secured to a metal mounting
plate. The mounting plate then is attached to a flat metal surface
in a low-voltage section of the Liebert unit.
The self-contained model packages the interface card inside a
steel enclosure, for mounting external to the Liebert unit. A lowvoltage transformer is also provided.
RETROFIT INSTALLATION
Environmental Installation
Deluxe System/3:
Position the OpenComms card in the low voltage/control cavity
of the Liebert Deluxe System/3 unit. Refer to Figures 2, 3 and 4
for typical positioning. Use three #8 x ½” sheet metal screws to
affix mounting plate to the Environmental unit.
8
Installation
Figure 2. Deluxe System/3 Control Cavity
Figure 3. Deluxe System/3 Chilled Water Control Cavity
Installation
9
Figure 4. ICS Control Cavity
10
Installation
Figure 5. Challenger Installation Location
The OpenComms Network card mounts to the Lplate for Challenger units.
Installation
11
System Wiring (SM, AM, AG Microprocessors)
Two wiring harnesses are included with the retrofit kit, one for
the power connection and the second for communications. They
are of sufficient length for use with the Deluxe System/3 and
ICS units and the microprocessors listed above. For the
Challenger product series, use the longer wiring harnesses
included with the NIC-K-Chall kit.
NOTE: Board illustrations are shown only for
location of connections. Board location and
wire length will change depending upon the
specific installation.
Power Connection (SM, AM, AG Microprocessors)
The harness supplied with the OpenComms Network Interface
Card (p/n 159084G1) is equipped with three connectors, one at
either end of the harness and one in the middle. The harness taps
power from the 24 VAC input to the control board of the
environmental unit. To connect this power to the NIC:
1. Locate the connector containing the two red wires plugged
into P43 on the control board and unplug it. Reconnect it to the
connector in the middle of the supplied harness.
2. Plug one end of this harness into P43 on the control board and
the other end into TB3 of the OpenComms card.
Power Connection (Level 0 and Level 10 Microprocessors)
To connect power to the NIC, wire as described above.
However, some field modification of the wiring harnesses is
necessary for connection to legacy systems.
Level 0: Remove the power connector normally plugged into
P43 and wire to terminal connections 1-5 (24V)/1-10 (ground).
12
Installation
Caution: Do NOT tap power from the auxiliary
24VAC terminals T5/G5 on the SM/AM/AG
environmental controllers. Damage to controller
and interface card may occur.
Communication Connection (SM, AM, AG
Microprocessor)
The second wiring harness provided (p/n 159083G1) has a
connector fitted at either end and is the communications
connection between the unit microprocessor and the NIC.
To put it in the system:
1. Remove the existing wire located on P25 of the environmental
controller, cut off the red connector and reconnect the wires to
TB2 of the interface card. Ensure correct polarity.
2. Connect one end of the wire harness to TB1 of the interface
card; the other end connects to P25 of the environmental
controller.
Communication Connection (Level 0 and Level 10
Microprocessors)
To connect communications wire to the NIC, wire as described
above. However, some field modifications of the wiring
harnesses are necessary for connection to legacy systems. Level
0 and Level 10: Remove the red connector normally plugged into
P25. Wire to terminal connection P25.
Installation
13
MiniMate2 and Units Where Internal Mounting is Not
Feasible
An enclosure is recommended for use with ceiling-mounted
environmental units or where internal mounting of the Network
Interface Card is not feasible. Older-generation Deluxe and
Challenger units may require external mounting.
Power Connection for External Enclosures
Power for the OpenComms Network card should be sourced
from the supplied wall-plug transformer. Use field-supplied
wiring to connect the outer terminals on the transformer to the
screw connectors at TB3 on the Network Interface card. A fieldsupplied ground wire attaches to the center terminal on the
transformer and connects to the grounding stud in the lower
corner of the enclosure.
Figure 6. NIC-ENCL1 Internal View
14
Installation
NPower Installation
As a minimum there will be an IFM board (communications
interface) mounted at the mid-point on the door. Other options
may also have been previously installed.
The Option boards mount on the inside of the option door.
Options can be located in any available option slot, however the
OpenComms – Network Interface Card should be mounted in
the topmost (top cable entry) or bottom most (bottom cable
entry) position.
Power Connection for NPower
After mounting the NIC card in the uppermost or lowermost
option position, per the instructions above, route the wire harness
from TB3 on the lower left of the NIC card to the power supply
board on the back of the control door. Follow the routing path
indicated in Fig 7.
Communication Connection for NPower
Connect the 2-wire harness from TB1 on the bottom center of
the NIC card to TB55 on the IFM card. The board is now ready
to connect customer inputs, which should be routed from either
the top or bottom cable entry points.
Refer to the Npower option manual for any further details on
installation.
Installation
15
Figure 7. Npower UPS Installation
16
Installation
USER CONNECTIONS FOR OPENCOMMS NIC
Since the OpenComms NIC can use simultaneous connections,
Up to 3 user connections are may be required: a permanent
network connection, a Modbus 485 connection and a temporary
serial connection for configuration/setup.
Confer with the network administrator or other responsible party
for arranging a network drop to the Liebert equipment. The
OpenComms Network card communicates via standard 10baseT
Ethernet network connection. Route the 10baseT cable to the
Liebert unit and connect to J3, the RJ45 jack on the interface
card. The OpenComms Network card will operate with any
10baseT Ethernet, regardless of operating system used.
The Modbus 485 connection will use the terminals marked
“Repeater.” (TB2) The Modbus server uses RTU protocol and
will allow for a maximum of 32 units on 4000ft. of wire on a
common line. EIA-485 repeaters may be necessary in order to
accommodate additional units or cable length. Point availability
may be referenced in the document, “NIC Reference Library,”
which may be downloaded at www.liebert.com under the
OpenComms product family.
A serial connection to the interface card is necessary for
configuration and setup, but does not need to be permanently
installed. Using a DB9F-DB9F null-modem serial cable,
connect the “DTE Serial Port” P18 to an ASCII terminal or
computer running terminal emulation application. Proceed to
configuration as detailed in Section 3. Disconnect the serial
connection when configuration is completed. Hyperterminal®
and Procomm® are examples of terminal emulation applications
running on Microsoft Windows® operating systems.
All
trademarks are property of their respective owners.
Installation
17
Section 3: SYSTEM CONFIGURATION
DIP SWITCH SETTINGS
A four-position DIP switch is provided, but no user
configuration via DIP switches is necessary at this time.
SERVICE TERMINAL
Refer to User Connections in Section 2 for instructions to
physically connect to the serial port. By default, the service
terminal communication parameters are:
9600 bps
8 data bits
No parity
1 stop bit
After connecting to the OpenComms NIC card,
press the space bar or <enter> key to activate
the service terminal session. If no response is
apparent and you have verified connections,
cycle power on the OpenComms NIC and the
service terminal sessions should appear
automatically.
Continued next page…
18
System Configuration
Service Terminal Navigation
Main Menu
1. System Information
1.1 Name
1.2 Contact
1.3 Location
1.4 Description
2. Network Interface
2.1 Speed / Duplex [fixed]
2.2 Boot Mode
2.2.1
Static
2.2.2
BootP
2.2.3
DHCP
2.3 IP Address
2.4 NetMask
2.5 Default Gateway
3. SNMP Communications
3.1 Enable SNMP agent [y/n]
3.2 Enable Authentication Traps [y/n]
3.3 Display / Modify Communities
3.4 Display / Modify Trap Communities
4. Web Server
4.1 Enable Web Server [y/n]
4.2 Change User Name / Password
4.2.1
Enter User Name (prompt)
4.2.2
Enter New Password (prompt)
4.2.3
Verify Password (prompt)
5. Firmware Updates
5.1 Initiate Xmodem Session
6. Factory Settings
6.1 Reset to Factory Defaults [y/n]
6.1.1
Manufacture Date
6.1.2
MAC Address
6.1.3
Serial Number
7. Auxiliary Communications
7.1 Enable Application [y/n]
7.1.1
None
7.1.2
Modbus Server
7.2 Enter Server ID
7.3 Communication Rate
System Configuration
19
1. System Information Menu
The System Information Menu seeks descriptive input to enable
the unit to be identified. This data is readable via SNMP queries.
The (“) character is not permitted in any of the descriptive fields
2. Network Interface Menu
The Network Interface Menu configures network parameters
essential for proper network operation.
The network
administrator or other personnel responsible for the network
should be consulted for the proper parameters to be entered in
this menu.
In the static mode, the IP address is entered. Use the standard
four-part dotted decimal format. The NetMask and Default
Gateway should also be entered in dotted decimal format. The
NetMask, also known as subnet mask, delineates devices on the
same physical network segment, versus devices that require the
services of a network router for access to other networks. The
Default Router is the address of default router on the local
segment.
Caution: Consult your network administrator to
ascertain the parameters appropriate to your
network.
BOOTP and DHCP Mode
The OpenComms NIC supports DHCP & BOOTP. To use this
ability, a DCHP or BOOTP server must exist on the network.
When this feature is enabled, at boot-up the card will perform a
DHCP or BOOTP request for configuration information,
including automatic assignment of IP address. If the card
receives the information, then no further requests are made. If, at
boot-up, a response is not received, the card will continue to
send a request approximately every 30 seconds until a response
20
System Configuration
is received. When this condition is encountered, pushing the
"enter" key returns the unit to the service terminal mode.
3. SNMP Communications Menu
The SNMP (Simple Network Management Protocol)
Communications Menu specifies parameters particular to the
SNMP interface. Communities are used as a means of security
for SNMP v1; only specified hosts with the appropriate
community name(s) are allowed to perform particular SNMP
operations. Up to 20 different communities can be assigned.
For each community, specify the dotted decimal IP address of
the remote host, the privilege level (read or read/write), and
community name. Trap Communities specify the recipient(s) of
SNMP trap messages generated by the OpenComms Network
Interface Card. Typically, the recipient is the management
station of the NMS. Specify the destination IP address, and the
community name for that host. Up to 20 trap communities can be
assigned.
For Communities and Trap Communities, the
information can be entered as a “complex” line — all parameters
space-delimited on the command line. Otherwise, the menu
items will prompt for each individual parameter.
Note: SNMP v1 communities are transmitted in
plain (unencrypted) text across the network.
Authentication failure traps may be enabled, so that the network
management system can be warned when unauthorized access
(i.e.: incorrect community name) is attempted.
4. Web Server
The Web Server section will allow the user to disable / enable
the HTTP session for the card. Disabling the Web Server means
that web browsers will not be able to access the devices status
graphical page (GUI).
System Configuration
21
5. Firmware Update Menu
The Firmware Update Menu is intended for Liebert service
personnel only. No user configurable parameters are accessed in
this selection. If entered, to escape, power must be cycled on the
card.
6. Factory Settings Menu
The Factory Settings Menu displays the manufacture date, serial
number and MAC address of the card. These parameters are
read-only. Once all parameters have been entered, press
<escape> to return to the Main menu; then press <x> to save
configuration, exit and reboot to enable the new configuration.
All parameters are stored in non-volatile flash memory.
Alternately, pressing <q> after <escape> will abort all changes.
Neither selection is case-sensitive.
7. Auxiliary Communications
The Auxiliary Communications Menu allows the user to set up
the parameters necessary for Modbus communications. The user
can enable / disable the Modbus sessions as well as assign the
slave ID.
Once all parameters have been entered, press <escape> to return
to the Main menu; then press <x> to save configuration, exit
and reboot using the new configuration. All parameters are
stored in non-volatile flash memory. Alternately, <q> will abort
all changes. Both selections are not case-sensitive.
22
System Configuration
Section 4: OPERATION
SNMP
The OpenComms Network Interface Card supports “get,”
“getnext,” “set,” “response” and “trap” packets of SNMP
(Simple Network Management Protocol). The OpenComms NIC
supports MIB-II, RFC1628 and Liebert Global Products MIBs.
The terms, “alarms” and “conditions” will be used
interchangeably through out this description. Alarms are
generated and maintained through the RFC 1628 UPS MIB.
Conditions are generated and maintained through the Liebert
Global Products MIB. The RFC 1628 UPS MIB provides
information for the supported UPS devices. The Liebert Global
Products MIB provides information for the supported
environmental devices. All conditions that are listed are
dependent upon what the unit itself supports. When a condition
occurs within the unit, it is logged into the condition table within
the appropriate MIB and a unique ID is assigned. A description
of the condition along with the value of the system up-time when
the condition was generated is placed into the table as well. A
trap is then sent out to the monitoring system.
Liebert Global Products MIB
Environmental units log conditions in the Liebert Global
Products MIB. Traps for the environmental units are generated
out of the Liebert Global Products MIB. Currently, there are only
two traps that are sent for environmental units through the MIB:
Event Condition Entry Added and Event Condition Entry
Removed. The Event Condition Entry Added is sent each time a
condition is inserted into the conditions table. This trap provides
the condition ID, the condition description, and the condition
time. The Event Condition Entry Removed is sent each time a
condition is removed from the conditions table. This trap
NIC Setup and Testing
23
provides the condition ID, the condition description, and the
condition time.
RFC 1628 UPS MIB
UPS units log alarms in the RFC 1628 UPS MIB. Traps for the
UPS units are generated out of the RFC 1628 UPS MIB. There
are four traps that may be sent for the UPS units: Trap On
Battery, Trap Test Completed, Trap Alarm Entry Added and
Trap Alarm Entry Removed.
The Trap on Battery is sent when the UPS is operating on battery
power. This trap will be sent once per minute until the UPS
either shuts down or is no longer running on battery power. This
trap pro-vides the Estimated Minutes Remaining on Battery, the
Seconds on Battery and the Configured Low Battery Time. The
Trap Test Completed is sent when a UPS diagnostic test is
completed. This trap provides the Test ID of the test that has
been performed, the Test Spin Lock, the Test Results Summary,
the Test Results Detail, the Test Start Time and the Test Elapsed
Time. The Trap Alarm Entry Added is sent when an alarm is
placed into the alarm table and provides the alarm ID and the
alarm description. This trap is not sent on the following alarms:
On Battery and Test In Progress. The Trap Alarm entry
Removed is sent when an alarm is removed from the alarm table
and provides the alarm ID and the alarm description. This trap is
not sent out when the Test In Progress alarm is removed from
the alarm table.
MIB
The Management Information Base (MIB) is a formal document
declaring the specifics of the information supported by the
SNMP implementation. The administrator for the NMS (or other
applications utilizing SNMP to communicate with the Liebert
units will need the MIB in order to integrate the Liebert units
into the monitoring system.
24
NIC Setup and Testing
The MIBs for the OpenComms Network Interface Card are
available for download on the Liebert Web site,
www.liebert.com. Navigate through Products, then Site
Monitoring & Software and proceed to the OpenComms support
information area. The RCF 1628 MIB can be downloaded at
www.ietf.org (the Internet Engineering Task
Force).
Physical media containing MIB files do not ship with the
hardware.
HTTP
Status and alarm information can be queried by web browsers
via HTTP v1.1 (Hyper Text Transfer Protocol). The data is
shown in an intuitive graphical format, akin to the unit’s front
bezel controls. Currently, the following browsers have been
tested and are supported:
Microsoft Internet Explorer, versions 5.x and later
Limited Support for: Netscape 6.0 & Opera 5
Font sizing may need to be adjusted on your browser for optimal
viewing.
With appropriate NMS software and configuration, the user on
reception of SNMP traps may view HTTP pages in order to view
the overall operating status of the unit – or HTTP may be used
on its own to monitor “on-demand” the unit operation. HTTP
pages will automatically refresh (reload) every 20 seconds and is
adjustable through the service terminal program.
NIC Setup and Testing
25
MODBUS RTU
See Section 5 for a complete explanation of the Modbus slave.
SYSTEM RESET
The OpenComms Network card contains an on-board real time
clock and watchdog circuitry. The card is self-monitoring and
self-correcting. Nevertheless, a pushbutton is provided in the
event that a manual system reset in desired. The Reset
pushbutton is labeled S1 on the interface card: press and hold for
3 seconds before to releasing to initiate hardware reset.
DIAGNOSTICS
A number of LEDs are provided on the interface card to provide
information for diagnostic purposes. The following table
summarizes their indications:
LED Identifier
DS1
DS2
DS3
DS4
DS5
DS6
DS7
DS8
DS9
DS10
DS11
DS12
26
Description
Ethernet Port Collision
Ethernet Port Receive
Ethernet Port Transmit
Ethernet Port Link
Not used
Not used
Repeater Port Receive
IGM Port Receive
Microprocessor in Operation
Serial Port Receive
Serial Port Transmit
Repeater Port Transmit
NIC Setup and Testing
DS13
DS14-19
IGM Port Transmit
Not used
Figure 8. LED Locations
NIC Setup and Testing
27
Section 5: MODBUS COMMUNICATIONS &
CONNECTIVITY
This section describes the Modbus communications protocol as
supported by the OpenComms NIC card. It includes information
on how to pass information to and from the OpenComms NIC
card via Modbus. It is also intended to help facilitate answering
questions regarding supported types, frame format, function code
support etc.
IMPLEMENTATION BASICS
Protocol controls the language structure or message format
between devices in other words, the rules for communication.
The rules for communication include how master and slave
devices initiate communications, as well as unit identification,
message handling and error checking. Modbus protocol simply
refers to the control of the query and response cycles between
master and slave devices.
The OpenComms NIC module is configured to act as a slave
device on a common network. The common network is a multidrop or “daisy chain” configuration over EIA-485, where
multiple slaves reside on a common wire or loop.
CONSTRAINTS
The OpenComms NIC communicates with local database and
therefore is subject to the time delay resulting from the local
database updating policies. Use of “Preset Multiple Holding
Registers” and “Preset a single Holding Register” functions
requires accessing the Liebert device connected and to the
OpenComms NIC card database service. Users should be aware
that the Modbus application coexists with other on-board
application servers (HTTP and SNMP specifically) and
competes for the database service and CPU time. This may lead
to uncertainty of responding time of the OpenComms NIC. The
user or third party integrator may have to compensate for the
28
NIC Setup and Testing
delay time if HTTP, SNMP and Modbus are going to be utilized
simultaneously.
TRANSMISSION FORMAT
The OpenComms NIC module supports Modbus RTU (Remote
Terminal Unit) transmission modes. The OpenComms NIC
communication rate is fixed at 9600 baud, 8 data bits, No
parity, 1 Stop bit. The communication media is fixed using
EIA-485 standards.
PHYSICAL CONNECTION
A Modbus network should consist of one, and only one, host
client, and up to 255 slaves uniquely identifiable by their slave
ID. The slave ID of each OpenComms NIC is set through the
service terminal (configuration) port. (See section 3, System
Configuartion for more details.) The OpenComms NIC supports
multi-drop connection over RS485. On the OpenComms NIC, a
client should connect to the OpenComms NIC as a multi-drop
connection via the RS485 “Repeater” port (TB2), (Pin1 as minus
and Pin2 as plus. J28-1 and J28-2 should be shorted.)
The OpenComms NIC card is designed to reside on a maximum
common line of 32 devices with a total cable length of 4000 feet.
In a “normal environment” all devices should be connected in
“daisy-chain” fashion, with “star configurations” or branches,
being used at a minimum. See Figure 9 for details. A “normal
environment” consists of an installation where noise or electrical
interference is minimal. This is typical of communication wiring
run in properly grounded conduit or in areas where high voltage
or radio transmissions are not present. Otherwise, these
conditions are designated as “noisy.”
NIC Setup and Testing
29
Modbus RTU Master
EIA-485 9600,N,8,1
Maximum of 32 devices
with a total cable length of
4000feet.
Figure 9. Typical Maximum Installation
The recommended cable characteristics are:
Normal Environments:
•
18-22 gauge, twisted-pair, stranded
(non- shielded)
Typical type is: Belden 8442
Noisy Environments:
•
18-22 gauge, twisted-pair, stranded
(shielded)
Typical type is: Belden 9461
30
NIC Setup and Testing
Modbus RTU Master
EIA-485 9600,N,8,1
Maximum of 32 devices
with a total cable length of
4000feet.
R
Maximum of 32 devices
with a total cable length of
4000feet.
R
Maximum of 32 devices
with a total cable length of
4000feet.
Figure 10. Exceeding Maximum Specifications
The maximum specification may be exceeded if measures are
taken to drive or boost the EIA-485 communication line. Two
wire EIA485 repeaters are available through the Liebert
Corpration. SiteScan’s “REPOPT” will work sufficiently for
this application. Consult the SiteScan price book for pricing
schedule and alternative solutions.
MODBUS SLAVE FUNCTIONS
Data Type
The OpenComms NIC supports data in a register block as one of
the following types: Signed integer (16 bit) / Unsigned integer
(16 bit) / Signed long (32 bit); IEEE floating-point (32 bit); Null
terminated String.
NIC Setup and Testing
31
A datum should consist of one or multiple registers. The leftmost
byte contains the MSB and the rightmost byte contains the LSB.
Function Code Support
The OpenComms NIC implements the following Modbus
functions. However, integrators will use function code 0x03,
and 0x06 most often due to the type of data to be acquired.
0x01
Read Coil Status
0x02
Read Input Status
0x03
Read Holding Registers
0x04
Read Input Registers
0x06
Write Single Holding Register
0x0F
Force Multiple Coils
0x10
Preset Multiple Holding Registers
Read/Write Holding Registers (0x03, 0x06, 0x10)
A holding register is a 16-bit message unit. In principle, a
message in a holding register is write / readable, but holding
registers can be used by read-only data as well. Holding
registers are mapped into 40001- 49999 logic address range.
Holding registers can be read by function code 0x03. A
maximum of 125 registers can be read by a single query.
Function code 0x06 requests the server to change the content of
a single holding register, and function code 0x10 requests server
to change the contents of multiple holding registers adjacent to
each other.
Read Input Registers (0x04)
The input register block contains read-only data accessible to the
user. A datum in the input register block occupies one or
multiple registers such as described in the previous section. The
input registers are mapped into 30000-39999 of the logic address
range.
32
NIC Setup and Testing
Up to 125 input registers can be read by a single query using
function code 0x04.
Read, Set Coil Status (0x01, 0x05, 0x0F)
Coil status contains bit-mapped status accessible to the users. In
principle, a coil status can be read, set or cleared by the host
client. Multiple coil status can be read by specifying the index
of bits of the first coil and the number of consecutive coils in a
single query.
Coil status can be read by function code 0x01.
Function code 0x05 set or clear a single coil, and function code
0x0F set or clear multiple coils.
Read Input Status (0x02)
The input status block contains read-only status accessible to the
users. It can be read by using function code 0x02 in the same as
reading coil status.
Error Handling
According to the Modbus specification, the OpenComms NIC
composes the following exception responses to the client if an
exception or error occurs.
NIC Setup and Testing
33
Exception Response
Server
Address
1 byte
Function Code
(0x80)
1 byte
Exception
code
1 bytes
16 bit CRC
2 bytes
Exception code is one of the following:
01: Unsupported Function code
02: Out-of-range data addresses
03: Out-of-range data value (write to holding
registers)
04: There is currently no LMD device connected to
the server
05: Server is composing response but cannot
response to the client within the time limit required
by Modbus specification.
Modbus Packet Formats
Each Modbus packet consists of the following fields:
• Device Address
• Function Code
• Data Field(s)
• Error Check Field
Device Address:
The address field immediately follows the beginning of the
frame and consists of 8-bits. These bits indicate the user
assigned address of the slave device that is to receive the
message sent by the attached master device.
Each slave OpenComms NIC must be assigned a unique address
and only the addressed slave will respond to a query that
contains its address.
34
NIC Setup and Testing
Function Code:
The function code field tells the addressed slaves what function
to perform. Function codes are specifically designed invoke a
specific action by the slave device. The function code range is
from 1 to 127. However, the OpenComms NIC module
primarily uses Function Code 3 (Read Holding Registers) and
Function Code 6 (Preset Single Register).
Data Field(s):
The data field varies in length depending on whether the
message is a request or a response to a packet. This field
typically contains information required by the slave device to
perform the command specified or to pass back data to the
master device.
Error Check Field:
The Error Check Field consists of a 16-bit (2 byte) Cyclical
Redundancy Check (CRC16). It allows the receiving device to
detect a packet that has been corrupted with transmission errors.
NIC Setup and Testing
35
RTU Framing Examples
READ REGISTERS (FUNCTION CODE 0X03 &
0X04)
Query: for reading holding /input registers (requested by a client)
Server Function
Index of
Number of
16 bit
Addres
Code
starting register registers to be read CRC
s
(0x3/0x4)
1 byte
1 byte
2 bytes
2 bytes
2
bytes
Response: for reading holding/input registers (response by the server)
Server Function
Byte
Data from registers
16 bit
Addres
Code
Count
CRC
s
(0x3/0x4)
1 byte
1 byte
1
2*m bytes (= Byte Count)
2 bytes
bytes
WRITE SINGLE HOLDING REGISTER
(FUNCTION CODE 0X06)
Query: for writing a single holding register (requested by a client)
Server Function
Index of the
16 bit value to
16 bit CRC
Addres
Code
register
be written
s
(0x06)
1 byte
1 byte
2 bytes
2 bytes
2 bytes
Response: for writing a holding registers (response by the server)
Server Function
Index of the
16 bit value
16 bit CRC
Addres
Code
register
been written
s
(0x06)
1 byte
36
1 byte
2 bytes
2 bytes
2 bytes
NIC Setup and Testing
Section 6: NIC Setup and Testing
The NIC has a specific setup that must be in place before the
card will function properly. There are jumpers on the board that
must be in the correct locations. The positions of these jumpers
are numbered on the board itself. A small triangle silk screened
on the board represents pin 1 for each set of pins to which
jumpers may be applied.
JUMPER PLACEMENTS
J13, J14, and J18 on the board must have jumpers installed on
them.
J32 must have a jumper installed on pins 2 and 3.
J28 jumper positions will apply to future capabilities, but are not
currently usable on the NIC.
Your card was shipped with the jumpers properly installed.
TESTING THE NETWORK
“Ping” is a tool used to test the network. At the command
prompt, type, “ping <address of card>”. Ping will respond that it
received a reply from the card if the card is functioning properly
on the network.
If the card is not functioning properly or is not connecting to the
network, ping will respond that the request it sent to the card has
timed out.
If the ping request times out, go to the Service Terminal to verify
that the card initialized the network when it powered up. If the
card is sitting at the text “Initializing network…” then the card
has not connected to the network. Hit <enter> to go into the
Service Terminal. Select number 2 for the Network Interface
Menu. Verify that you have the boot mode set up correctly. If
you choose a static IP Address, verify that the IP Address is
valid for your network.
If you obtain your network information from a BootP or DHCP
server, verify that the server is valid and that it is responding to
NIC Setup and Testing
37
requests. Once the information has been verified, press <escape>
to return to the main menu and select “x” to exit out of the card.
Then, reboot the card. The card may be rebooted by pressing
switch S1 on the card for approximately 2 seconds until the DS9
link light turns off.
If the card still does not connect to the network, or ping still does
not receive a reply from the card, verify proper set up on the card
itself. DS4 should be illuminated if the card detects the network.
Verify that the network cable is connected to Ethernet port J3
and that the hub/router/switch to which the card is connected is
operating correctly.
Once this information is verified, reboot the card.
SERVICE TERMINAL TROUBLESHOOTING
If the card does not bring up a Service Terminal, check link light
DS9. DS9 should be illuminated within approximately 0.5
seconds of application of power. If DS9 is not illuminated and no
other LED's are on, verify that power has been applied to the
card. If power has been applied, verify wiring connected to TB3
is correct. TB3 should have 24VAC or 12 VDC applied. Reboot
the card once the power to the card has been verified.
SNMP TROUBLESHOOTING
If SNMP is not functioning, first make sure that the card powers
up, the Service Terminal is functioning and the card is connected
to the network (verified by using ping). If all of those conditions
are met, verify that the community strings are set up correctly.
To do this, go into the Service Terminal and select number 3 for
SNMP Communications.
Then, select number 2 for
Display/Modify
Communities. Verify that the IP Addresses listed are valid for
your network. Verify that you are typing in the correct
community name when trying to access SNMP. The community
name is case sensitive.
38
NIC Setup and Testing
Once this information is verified, reboot the card and try to
access SNMP again.
WEB TROUBLESHOOTING
If the card does not serve up a web page, but the Service
Terminal is functioning, SNMP is functioning, and the card is
connected to the network (verified through ping), then reboot the
card. In this case, the web server has been lost and needs to be
restarted.
If the card serves up a web page, but the web page only displays
“Discovering connected device…” verify that the card is
connected to the desired device. Verify that the link lights DS13
and DS8 are blinking on and off. DS13 indicates that the card is
receiving from the connected device. DS8 indicates that the card
is transmitting to the connected device.
If neither of the link lights is blinking, check the connection
between TB1 and P3. TB1 is used to interface to the
Environmental units and to some UPS’s. P3 is used to interface
with some UPS’s. If DS13 is blinking and DS8 is not, this
indicates a communication problem between the card and the
connected device. Replace the NIC card and retry connecting to
the web. If the problem persists, change the card in the device
that the NIC card is trying to interface with. Try to reconnect to
the web.
MODBUS TROUBLESHOOTING
If the card does not respond to Modbus requests, verify that
DS7, “repeater port receive” is flashng during a request. In
proper communications DS12 will also be flashing indicating
“repeater port transmit”
Verify proper wiring on the EIA 485 network. OpenComms NIC
cards should observe a “plus to plus” and “minus to minus” daisy
chain configuration.
NIC Setup and Testing
39
Also verify that the proper slave ID has be set in service
terminal. Refer to Section 3 for initiating a service terminal
session
40
NIC Setup and Testing
OpenComms NIC
Network Interface Card
THE COMPANY BEHIND
THE PRODUCTS
With more than 500,000 installations
around the globe, Liebert is the
world leader in computer protection
systems. Since its founding in 1965,
Liebert has developed a complete
range of support and protection
systems for sensitive electronics:
•
•
•
•
•
Environmental systems: precision air
conditioning from 1.5 to 60 tons.
Power conditioning and UPS with
power ranges from 250 VA to more
than 1000 kVA.
Integrated systems that provide
both environmental and power
protection in a single, flexible
package.
Monitoring and control – on-site
or remote – from systems of any
size or location.
Service and support, through
more than 100 service centers
around the world, and a 24-hour
Customer Response Center.
LIEBERT CORPORATION
1050 DEARBORN DRIVE
P.O. BOX 29186
COLUMBUS, OHIO 43229
800.877.9222 PHONE
614.841.6022 FAX
LIEBERT EUROPE
GLOBE PARK
MARLOW
BUCKINGHAMSHIRE SL7
1YG
UNITED KINGDOM
+44.1628.403200 PHONE
+44.1628.403203 FAX
LIEBERT ASIA
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852.2.831.0114 FAX
LIEBERT WEB SITE
http://www.liebert.com
While every precaution has been taken to ensure accuracy and completeness in this literature, Liebert
Corporation assumes no responsibility, and disclaims all liability for damages resulting from use of this
information or for any errors or omissions.
© 1999 Liebert Corporation. All rights reserved throughout the world. Specifications subject to
change without notice.
All names referred to are trademarks or registered trademarks of their respective owners.
SL-28082 (Rev 3 July, 2001 by SJZ)
NIC Setup and Testing
41
Printed In USA