System Design and Configuration 14 In This Chapter. . . . — DL405 System Design Strategies — Module Placement and Configuration — Calculating the Power Budget — Local I/O Expansion — Remote I/O Expansion — Network Connections to MODBUSR and DirectNET — Network Slave Operation — Network Master Operation 4--2 System Design and Configuration DL405 System Design Strategies I/O System Configurations The DL405 PLCs offer the following ways to add networking to the system: S Local I/O -- consists of I/O modules located in the same base as the CPU. S Expansion I/O -- consists of I/O modules in expansion bases located close to the the local base. Expansion cables connect them to the local CPU base’s serial bus in daisy-chain fashion. S Remote I/O -- consists of I/O modules located in bases which are serially connected to the local CPU base through a Remote Master module, or may connect directly to port 3 on a DL450 CPU. A DL405 system can be developed using many different arrangements of these configurations. All I/O configurations use the standard complement of DL405 I/O modules and bases. Below is a brief description of each of these configurations. Examples of each configuration are discussed in detail later in this chapter. Local I/O CPU (RM) 3280 ft. (1000m) Total distance 7 Bases per channel R M Remote I/O channel (DL450) RS 1 meter max. length, each cable System Design and Configuration EXP EXP Expansion I/O -- 3 Expansion racks maximum -- DL430/440 up to 320 input and 320 outputs (includes I/O in the local CPU base) -- DL450 up to 1024 input and 1024 outputs (includes I/O in the local CPU base) EXP DL405 User Manual, 4th Edition, Rev. A Remote I/O DL440/430 supports a maximum of 2 channels. These channels can be any combination of remote I/O. DL450 supports a maximum of 3 channels. One remote channel connects directly to the DL450 CPU. The other channel uses Remote Masters in any combination. System Design and Configuration Networking Configurations 4--3 The DL405 PLCs offer the following four ways to add I/O modules to the system: S Data Communications Module -- connects a DL405 system to devices using the DirectNET protocol, or connects as a slave to a MODBUS network. S DL450 Communications Ports -- the DL450 CPU has two extra (total of four) built-in comm ports. It allow two network connections directly from the CPU. See Chapter 3, CPU Specifications and Operation, for individual port specifications, and the sections at the end of this chapter for network connections. S MODBUS Master Module -- You can use MODBUS master modules in any slot of a DL405 system for connecting it as a master to a MODBUS network, using the RTU protocol. S MODBUS Slave Module -- You can use MODBUS slave modules in any slot of a DL405 system for connecting it as a slave to a MODBUS network, using the RTU protocol. S TIWAYR Network Interface Module -- Interface to Texas Instruments and Siemens TIWAY networks by using this module as a slave. S Shared Data Network Module -- The Shared Data Network Module lets you make peer--to--peer connections between DL405 PLC systems. PEER-TO-PEER and MASTER/SLAVE COMMUNICATIONS 305 System Migration or Expansion DirectNET/MODBUSr Communication (max. 3300ft/1000m) DirectNET/MODBUSr Communication (max. 3300ft/1000m) DirectNET Communication (max. 3300ft/1000m) 405 DCM MB DCM MSTR DL405 User Manual, 4th Edition, Rev. A System Design and Configuration 405 4--4 System Design and Configuration Module Placement and Configuration Valid Module/Unit Locations The most commonly used I/O modules for the DL405 system (AC, DC, AC/DC, Relay and Analog) can be used in any base in your system. The table below lists by category the valid locations for all modules/units in a DL405 system. Remember that the power budget can limit the number of modules in a base (discussed later). Module/Unit CPUs Local CPU Base Local Exp. Base Remote Base CPU Slot Only Expansion Units CPU Slot Only 8/16/32pt DC Input Modules 64pt DC Input Modules n n Note 1 n n n Note 1, 2 AC Input Modules n n n AC/DC Input Modules n n n 8/16/32pt DC Output Modules n n n 64pt DC Output Modules n Note 1 n Note 1, 2 AC Output Modules n n n Relay Output Modules n n n Analog Modules n n n Remote I/O Remote Master n Remote Slave Unit CPU Slot Only Communications and Networking Modules n CoProcessor Modules n n Note 2 Specialty Modules System Design and Configuration Interrupt DL430 -- Slot 0 Only DL440 -- Slots 0 & 1 DL450 -- Slots 0 & 1 High Speed Counter n PID Module n SDS n 4 Loop Temp. Controller n Input Simulator n n n Filler n n n n Note 1: When using 64 pt modules, you cannot use any specialty modules in slots 5, 6, and 7 in the same base. Note 2: Specialty modules are allowed in expansion bases only if you are using the DL450 CPU and all bases in the system are the D4--xxB--1 type bases. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration I/O Configuration Methods Automatic Configuration 4--5 There are two methods of I/O configuration for the DL405 CPUs: S Auto configuration -- the CPU automatically configures the I/O. It assigns the lowest I/O numbers to the module in slot 0 (the slot next to the CPU), the next set of I/O numbers to the next module in the base, etc. The numbers are assigned only to modules actually in the base, not to empty slots in the base. This is the default mode of the CPU. S Manual configuration -- (DL440/DL450 only) allows you assign I/O numbers. Numbers can be assigned to empty slots or in any order as long as the numbers are assigned in groups of 16 or 32. The DL405 CPUs automatically detect any installed I/O modules (including specialty modules)at powerup, and establish the correct I/O configuration and addresses. For most applications, you will never have to change the configuration. I/O addresses use octal numbering, starting at X0 and Y0 in the slot next to the CPU. The addresses are assigned in groups of 8, 16, 32, or 64 depending on the number of points for the I/O module. The discrete input and output modules can be mixed in any order, but there may be restrictions placed on some specialty modules. The following diagram shows the I/O numbering convention for an example system. Slot 0 8pt. Input X0--X7 Slot 1 32pt. Output Y0--Y37 Slot 2 16pt. Input X10--X27 Slot 3 8pt. Input X30--X37 Manual Configuration 430 440 450 It may never become necessary, but DL440 and DL450 CPUs allow manual I/O address assignment for any I/O slot(s) in local or expansion bases. You can manually modify an auto configuration to match arbitrary I/O numbering. For example, two adjacent input modules can have starting addresses at X10 and X200. In automatic configuration, the addresses are assigned on 8-point boundaries. Manual configuration, however, assumes that all modules are at least 16 points, so you can only assign addresses that are a multiple of 20 (octal). For example, X30 and Y50 are not valid addresses. You can still use 8 point modules, but 16 addresses will be assigned and the upper eight addresses will be unused. WARNING: If you manually configure an I/O slot, the I/O addressing for the other modules may change. This is because the DL405 CPUs do not allow you to assign duplicate I/O addresses. You must always correct any I/O configuration errors before you place the CPU in RUN mode. Uncorrected errors can cause unpredictable machine operation that can result in a risk of personal injury or damage to equipment. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration Both the Handheld Programmer and DirectSOFT provide AUX functions that allow you to automatically configure the I/O. For example, with the Handheld Programmer AUX 46 executes an automatic configuration, which allows the CPU to examine the installed modules and determine the I/O configuration and addressing. With DirectSOFT, the PLC Configure I/O menu option would be used. 4--6 System Design and Configuration Removing a Manual Configuration After a manual configuration, the system will automatically retain the new I/O addresses through a power cycle. You can remove (overwrite) any manual configuration changes by simply performing an automatic configuration. The following diagram shows how I/O addresses change after manually configuring a slot. Automatic Manual System Design and Configuration Power--On I/O Configuration Check Slot 0 8pt. Input X0--X7 Slot 1 32pt. Output Y0--Y37 Slot 2 16pt. Input X10--X27 Slot 3 8pt. Input X30--X37 Slot 0 8pt. Input X0--X7 Slot 1 32pt. Output Y0--Y37 Slot 2 16pt. Input X100--X117 Slot 3 8pt. Input X20--X27 The DL405 CPUs can also be set to automatically check the I/O configuration on power-up. By selecting this feature you can detect any changes that may have occurred while the power was disconnected. For example, if someone places an output module in a slot that previously held an input module, the configuration check will detect the change and print a message on the Handheld Programmer or DirectSOFT screen (use AUX 44 on the HPP to enable the configuration check). If the system detects a change in the I/O configuration at power-up, an error code E252 NEW I/O CONFIGURATION will be generated. You can use AUX 42 to determine the exact base and slot location where the change occurred. WARNING: You should always correct any I/O configuration errors before you place the CPU into RUN mode. Uncorrected errors can cause unpredictable machine operation that can result in a risk of personal injury or damage to equipment. When a configuration error is generated, you may actually want to use the new I/O configuration. For example, you may have intentionally changed an I/O module to use with a program change. You can use AUX 45 to select the new configuration, or, keep the existing configuration stored in memory. WARNING: Verify the I/O configuration being selected will work properly with the CPU program. Always correct any I/O configuration errors before placing the CPU in RUN mode. Uncorrected errors can cause unpredictable machine operation that can result in a risk of personal injury or damage to equipment. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration 4--7 Calculating the Power Budget Managing your Power Resource As you have seen, the I/O configuration depends on your choice of I/O modules, bases, and I/O location. When determining the types and quantity of I/O modules you will be using in the DL405 system it is important to remember there is a limited amount of power available from the power supply to the system. We have provided a chart to help you easily see the amount of power you will have with your CPU, Expansion Unit or Remote Slave selection. The following chart will help you calculate the amount of power you need with your I/O selections. At the end of this section you will also find an example of power budgeting and a worksheet for your own calculations. If the I/O you chose exceeds the maximum power available from the power supply you can resolve the problem by shifting some of the modules to an expansion base which contains another power supply. WARNING: It is extremely important to calculate the power budget correctly. If you exceed the power budget, the system may operate in an unpredictable manner which may result in a risk of personal injury or equipment damage. CPU Power Specifications The following chart shows the amount of current available for the two voltages supplied on the DL405 CPU, Expansion unit or Remote Slave unit. Use these currents when calculating the power budget for you system. The Auxiliary 24V Power Source mentioned in the table is a connection at the base terminal strip allowing you to connect to devices or DL405 modules that require 24VDC. Auxiliary 24V Power Source Current Supplied in mA. Remote and Expansion Units 5V Current Supplied in mA. Auxiliary 24V Power Source Current Supplied in mA. D4--430 3700 400 D4--EX 4000 400 D4--440 3700 400 D4--EXDC 4000 None D4--440DC--1 3700 None D4--EXDC--2 3700 None D4--440DC--2 3700 None D4--RS 3700 400 D4--450 3100 400 D4--RSDC 3700 None D4--450DC--1 3100 None H4--EBC 3470 400 D4--450DC--2 3100 None H4--EBC--F 3300 400 Module Power Requirements The chart on the next page shows the amount of maximum current required for each of the DL405 modules. Use these currents when calculating the power budget for your system. If external 24VDC is required, the external 24V from the CPU power supply may be used as long as the power budget is not exceeded. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration CPUs 5V Current Supplied in mA. 4--8 System Design and Configuration Device 5V Current Required (mA) External 24V Current Req. (mA) I/O Bases 80 None D4--06B, D4--06BNX, D4--06B--1 80 None 80 None DC Input Modules F4--04AD 85 100 F4--04ADS 270 120 F4--08AD 75 90 F4--04DA 120 180 F4--04DA--1 70 75 + 20 per channel F4--04DA--2 90 75 + 20 per channel D4--08ND3S 100 None F4--04DAS--1 60 50 per channel D4--16ND2 150 None F4--04DAS--2 60 60 per channel D4--16ND2F 150 None F4--08DA--1 90 100 + 20 per channel D4--32ND3--1 150 None F4--16DA--1 90 100 + 20 per channel D4--32ND3--2 150 None F4--16DA--2 80 25 max. D4--64ND2 300 (max) None F4--16AD--1 100 100 F4--16AD--2 75 100 D4--08NA 100 None F4--08THM--n 120 50 + 20 per channel D4--16NA 150 None F4--08RTD 80 None D4--16NA--1 150 None Remote I/O D4--ERM 320 None D4--16NE3 150 None D4--ERM--F 450 None F4--08NES 90 None D4--RM 300 None D4--08TD1 150 35 D4--DCM 500 None F4--08TD1S 295 None H4--ECOM 530 None D4--16TD1 200 125 H4--ECOM--F 670 None D4--16TD2 400 None H4--ECOM100 300 None D4--32TD1 250 140 F4--MAS--MB 235 None D4--32TD1--1 250 140 (5--15VDC) CoProcessors™ D4--32TD2 350 120 / (4A max including loads) F4--CP128 305 None D4--64TD1 800 (max) None F4--CP512 235 None F4--CP128--T 350 None D4--16SIM 150 None D4--HSC 300 None F4--16PID 160 None F4--8MPI 225 170 F4--4LTC 280 75 H4--CTRIO 400 None AC Input Modules AC/DC Input Modules DC Output Modules System Design and Configuration External 24V Current Req. (mA) Analog Modules D4--04B, D4--04BNX, D4--04B--1 D4--08B, D4--08BNX, D4--08B--1 5V Current Required (mA) Device Communications and Networking AC Output Modules D4--08TA 250 None D4--16TA 450 None Relay Output Modules D4--08TR 550 None F4--08TRS--1 575 None F4--08TRS--2 575 None D4--16TR 1000 None D4--HPP 320 None DV--1000 150 None Programming DL405 User Manual, 4th Edition, Rev. A Specialty Modules 4--9 System Design and Configuration Power Budget Calculation Example The following example shows how to calculate the power budget for the DL405 system. Base # 0 Module Type Auxiliary Power Source 24 VDC Output (mA) 5 VDC (mA) CPU/ D4--430 Expansion Unit/ Remote Slave Used Slot 0 D4--16ND2 + 150 + 0 Slot 1 D4--16ND2 + 150 + 0 Slot 2 F4--04DA--1 + 70 Slot 3 D4--08ND3S + 100 + 0 Slot 4 D4--08ND3S + 100 + 0 Slot 5 D4--16TD2 + 400 + 0 Slot 6 D4--16TD2 + 400 + 0 Slot 7 D4--16TR + 1000 + 0 + 80 + 0 + 320 + 0 3700 400 + 155 Other Base D4--08B--1 Handheld Prog D4--HPP Maximum power required 3700--2950 =930 400 -- 300 155 = 100 1. Using the tables at the beginning of the Power Budgeting section of this chapter fill in the information for the CPU/Expansion Unit/Remote Slave, I/O modules, and any other devices that will use system power including devices that use the 24 VDC output. Pay special attention to the current supplied by either the CPU, Expansion Unit, and Remote Slave since they do differ. Devices which fall into the “Other” category are devices such as the Base and the Handheld programmer which also have power requirements but do not directly plug into the base. 2. Add the current columns starting with Slot 0 and put the total in the row labeled “Maximum power required”. 3. Subtract the row labeled “Maximum power required” from the row labeled “CPU/Expansion Unit/Remote Slave Used”. Place the difference in the row labeled “Remaining Power Available”. 4. If “Maximum Power Required” is greater than “CPU/Expansion Unit/Remote Slave Used” in any of the three columns, the power budget will be exceeded. It will be unsafe to used this configuration and you will need to restructure your I/O configuration. DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration Remaining Power Available 2770 4--10 System Design and Configuration Power Budget Calculation Worksheet You may copy and use the following blank chart for your power budget calculations. Base # Module Type 5 VDC (mA) Auxiliary Power Source 24 VDC Output (mA) CPU/ Expansion Unit/ Remote Slave Used Slot 0 Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 Slot 7 Other Maximum Power Required System Design and Configuration Remaining Power Available 1. Using the tables at the beginning of the Power Budgeting section of this chapter fill in the information for the CPU/Expansion Unit/Remote Slave, I/O modules, and any other devices that will use system power including devices that use the 24 VDC output. Pay special attention to the current supplied by either the CPU, Expansion Unit, and Remote Slave since they do differ. Devices which fall into the “Other” category are devices such as the Base and the Handheld programmer which also have power requirements but do not directly plug into the base. 2. Add the current columns starting with Slot 0 and put the total in the row labeled “Maximum power required”. 3. Subtract the row labeled “Maximum power required” from the row labeled “CPU/Expansion Unit/Remote Slave Used”. Place the difference in the row labeled “Remaining Power Available”. 4. If “Maximum Power Required” is greater than “CPU/Expansion Unit/Remote Slave Used” in any of the three columns, the power budget will be exceeded. It will be unsafe to used this configuration and you will need to restructure your I/O configuration. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration 4--11 Local I/O Expansion 430 440 450 The following I/O base configurations will assist you in understanding the options available in the DL405 series. Local and expanded bases are the most common and cost effective way of installing I/O. With local and expanded I/O the CPU can automatically configure the I/O for you. Use Remote I/O when it is necessary to locate I/O at distances away from the CPU. Remote I/O will require additional ladder programming to operate. Local Base and I/O The local base is the base in which the CPU resides. Local I/O modules reside in the same base as the CPU. For example, placing 32 point modules in all eight slots in an 8-slot base will use 256 I/O points . The status of each I/O point is updated each I/O scan of the CPU. Local Expansion Base and I/O 16pt Input 8pt Input 32pt 16pt 8pt 16pt Input Output Output Output X0 X20 X30 Y0 Y20 Y30 ------X17 X27 X67 Y17 Y27 Y47 CPU Use local expansion when you need more I/O points or a greater power budget than the local base provides. The expansion bases require a Local Expansion Unit (in the place of a CPU), and a cable (either D4--EXCBL--1 or D4--EXCBL--2) to connect to the local CPU base. The CPU base is always the first base in the expansion chain. The following figure shows one CPU base, two expansion bases and examples of I/O numbering. DL430/440: supports a maximum of 3 expansion bases, and maximum of 320 input points and 320 output points (includes local base I/O) 8pt Input Expansion cable output connection CPU 16pt Input 8pt Input 8pt 8pt Output Output 16pt Output X0 X10 X30 Y0 Y10 Y20 ------X07 X27 X37 Y07 Y17 Y37 Maxi. 3.05 ft (1M) Expansion Base 16pt Input Expansion cable input connection Expansion cable output connection Maxi. 3.05 ft (1M) EXP 16pt Input 8pt Input 32pt Input 16pt 8pt Output Output 8pt Output 8pt Output X40 X60 X100 X110 Y40 Y60 Y70 Y100 --------X57 X77 X107 X147 Y57 Y67 Y77 Y107 Expansion Base 8pt Input Expansion cable input connection EXP 8pt Input 16pt Input 16pt Input 16pt Input 16pt Output X150 X160 X170 X210 X230 Y110 ------X157 X167 X207 X227 X247 Y127 DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration DL450: supports a maximum of 3 expansion bases, and maximum of 1024 input points and 1024 output points (includes local base I/O) Local Base 4--12 System Design and Configuration Remote I/O Expansion How to Add Remote I/O Channels 430 440 450 Remote I/O is useful for a system that has a sufficient number of sensors and other field devices located a relative long distance away (up to 1000 meters, or 3050 feet) from the more central location of the CPU. The methods of adding remote I/O are: S DL430 / DL440 CPUs: Remote I/O requires a remote master module (D4--RM) to be installed in the local CPU base. The CPU updates the remote master, then the remote master handles all communication to and from the remote I/O base by communicating to the remote slave module (D4--RS) installed in each remote base. S DL450 CPU: The CPU’s comm port 3 features a built-in Remote I/O channel. You may also use one or two D4--RM remote masters in the local base as described above (can use either or both methods). DL430 DL440 DL450 2 2 2 CPU built-in Remote I/O channels none none 1 Maximum I/O points supported by each channel 512 512 512 Maximum Remote I/O points supported 512 1024 1536 7 7 7 Maximum number of Remote Masters supported in the local CPU base (1 channel per Remote Master) System Design and Configuration Maximum number of remote I/O bases per channel The use of Remote I/O does not limit the use of local expansion I/O discussed in the previous section. In fact, Remote I/O point numbering is assignable. Depending on the CPU scan time, remote I/O updates may be slower than local and expansion I/O, due to the serial communications involved. Remote I/O points map into different CPU memory locations than local/local expansion I/O. So, the addition of remote I/O does not reduce the number of local I/O points. Refer to the DL405 Remote I/O manual for details on remote I/O configuration and numbering. The following figure shows 1 CPU base, and one remote I/O channel with seven remote bases. If the CPU is a DL450, adding the first remote I/O channel does not require installing a remote master module (we use the CPU’s built-in remote I/O channel on port 3). Remote I/O -- 7 Bases per channel -- 3280 ft. (1000m) Total distance Expansion I/O also available CPU Base R M DL405 User Manual, 4th Edition, Rev. A System Design and Configuration Configuring the CPU’s Remote I/O Channel 430 440 450 4--13 This section describes how to configure the DL450’s built-in remote I/O channel. Additional information is in the Remote I/O manual, D4--REMIO--M, which you will need in configuring the Remote slave units on the network. You can use the D4--REMIO--M manual exclusively when using regular Remote Masters and Remote Slaves for remote I/O in any DL405 system. The DL450 CPU’s built-in remote I/O channel has the same capability as a Remote Master module, the D4--RM. Specifically, it can communicate with up to seven remote bases containing a maximum of 512 I/O points, at a maximum distance of 1000 meters. If required, you can still use Remote Master modules in the local CPU base (512 I/O points on each channel), for a total of three channels providing 1536 total remote I/O points. First, we’ll need to set up the Remote I/O communications. You may recall from the CPU specifications in Chapter 3 that the DL450’s Port 3 is capable of several protocols. To configure the port using the Handheld Programmer, use AUX 56 and follow the prompts, making the same choices as indicated below on this page. To configure the port in DirectSOFT, choose the PLC menu, then Setup > Setup Secondary Comm Port. S S Port: From the port number list box at the top, choose “Port 3”. Protocol: Click the box to the left of “Remote I/O” to select it (called “M--NET” on the HPP). The dialog shown below will appear. 3 S S Station Number: Choose “0” as the station number, which makes the DL450 the master. Station numbers 1--7 are reserved for remote slaves. Baud Rate: The baud rates 19200 and 38400 baud are available. Choose 38400 initially as the remote I/O baud rate, and revert to 19200 baud if you experience data errors or noise problems on the link. Important: You must configure the baud rate on the Remote Slaves (via DIP switches) to match the baud rate selection for the CPU’s Port 3. Memory Address: Choose a V-memory address to use as the starting location of a Remote I/O configuration table (V37700 is the default). This table is separate and independent from the table for any Remote Master(s) in the system. Then click the button indicated to send the Port 3 configuration to the CPU, and click Close. DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration S 4--14 System Design and Configuration The next step is to make the connections between all devices on the Remote I/O link. The location of the Port 3 on the DL450 is on the 25-pin connector , as pictured to the right. Remember that ports 1 and 3 are “logical” ports that share the 25-pin connector. Port 3 is an RS--422 nonisolated port. The pin assignments are: Signal GND S Pin 7 S Pin 12 TXD+ S Pin 13 TXD-S Pin 24 RXD+ S Pin 25 RXD-- Port 3 1 14 0V TXD+ TXD-- 13 25 RXD+ RXD-- Now we are ready to discuss wiring the DL450 to the remote slaves on the remote base(s). The remote I/O link is a 3-wire, half-duplex type. Since Port 3 of the DL450 CPU is a 5-wire full duplex--capable port, we must jumper its transmit and receive lines together as shown below (converts it to 3-wire, half-duplex). DL450 CPU Port 3 Remote I/O Master 0V 7 Termination Resistor RXD+ RXD-- TXD+ TXD-- 13 25 T Remote I/O Slave (end of chain) Jumper T TXD+ / RXD+ 1 1 TXD-- / RXD-- 2 2 Signal GND 3 3 G G Recommended cable: Belden 9842 or equivalent System Design and Configuration Remote I/O Slave Internal 330 ohm resistor The twisted/shielded pair connects to the DL450 Port 3 as shown. Be sure to connect the cable shield wire to the signal ground connection. A termination resistor must be added externally to the CPU, as close as possible to the connector pins. Its purpose is to minimize electrical reflections that occur over long cables. Be sure to add the jumper at the last slave to connect the required internal termination resistor. Ideally, the two termination resistors at the cables opposite ends and the cable’s rated impedance should match. For cable impedances greater than 330 ohms, add a series resistor at the last slave as shown to the right. If less than 330 ohms, just parallel a matching resistance across the slave’s pins 1 and 2 instead. For example, to match the termination resistance to Belden 9842, use a 120 ohm resistor across terminals 1 and 2. Remember to size the termination resistor at Port 3 to match. The resistance values should be between 100 and 500 ohms. DL405 User Manual, 4th Edition, Rev. A Add series external resistor T 1 2 3 G Internal 330 ohm resistor System Design and Configuration Configure Remote I/O Slaves 4--15 After configuring the DL450 CPU’s Port 3 and wiring it to the remote slave(s), use the following checklist to complete the configuration of the remote slaves. Full instructions for these steps are in the Remote I/O manual. S Set the baud rate DIP switches to match CPU’s Port 3 setting. S Select a station address for each slave, from 1 to 7. Each device on the remote link must have a unique station address. There can be only one master (address 0) on the remote link. If you’re familiar with configuring remote bases, then you’ll recall the fixed table location in V-memory (V7404--V7477) to configure up to two remote I/O channels. However, we use a separate table for configuring the DL450 CPU’s built-in remote I/O channel. You will still need the table at V7404 to configure any Remote Master modules. Configuring the Remote I/O Table The beginning of the configuration table for the built-in remote I/O channel is the memory address we selected in the Port 3 setup. The table consists of blocks of four words which correspond to each slave in the system, as shown to the right. The first four table locations are reserved. The CPU reads data from the table just after powerup, interpreting the four data words in each block with these meanings: 1. Starting address of slave’s input data 2. Number of slave’s input points 3. Starting address of outputs in slave 4. Number of slave’s output points 37700 Remote I/O data Reserved V37700 V37701 V37702 V37703 xxxx xxxx xxxx xxxx Slave 1 V37704 (or last V37705 slave) V37706 V37707 xxxx xxxx xxxx xxxx V37734 V37735 V37736 V37737 0000 0000 0000 0000 Slave 7 (or last slave) DirectSOFT SP0 LDA O40000 OUT V37704 LD K16 OUT V37705 DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration The table is 32 words long. If your system has fewer than seven remote slave bases, then the remainder of the table must be filled with zeros. For example, a 3--slave system will have a remote configuration table containing 4 reserved words,12 words of data and 16 words of “0000”. A portion of the ladder program must configure this table (just once) at powerup. Use the LDA instruction as shown to the right, to load an address to place in the table. Use the regular LD constant to load the number of the slave’s input or output points. The D4--REMIO--M manual contains thorough examples for configuring the table at V7404, which you can adapt for this table as well. The following page give a shorter program example for one slave. Memory Addr. Pointer 4--16 System Design and Configuration Consider the simple system featuring Remote I/O shown below. The DL450’s built-in Remote I/O channel connects to one slave base, which we will assign a station address=1. The baud rates on the master and slave will be 38400 kB. We can map the remote I/O points as any type of I/O point, simply by choosing the appropriate range of V-memory. Remember that on the DL450, you have both GX and GY data types available. Since we have plenty of standard I/O addresses available (X and Y), we will have the remote I/O points start at the next X and Y addresses after the main base points (X60 and Y40, respectively). Main Base with CPU as Master Remote Slave Worksheet 1 Remote Base Address_________(Choose 1--7) DL450 CPU 16 16 I Port 3 16 I X0-X17 V40400 16 I 16 O O X20-X37 X40-X57 Y0-Y17 V40401 V40402 V40500 Y20-Y37 V40501 Remote Slave 0 INPUT Module Name Input Addr. No. Inputs 08ND3S X060 8 1 08ND3S 2 08TD1 Y040 8 3 08TD1 Y050 8 Slot Number X070 OUTPUT Output Addr. No. Outputs 8 4 5 6 D4--RS Slave 8 8 8 8 I I O O 7 X060 Input Bit Start Address:________V-Memory Address:V_______ 40403 16 Total Input Points_____ Y040 40502 Output Bit Start Address:________V-Memory Address:V_______ X60-X67 X70-X77 Y40-Y47 Y50-Y57 V40403 V40404 V40502 V40503 System Design and Configuration Remote I/O Setup Program Using the Remote Slave Worksheet shown above can help organize our system data in preparation for writing our ladder program (a blank full-page copy of this worksheet is in Appendix A of the D4--REMIO--M manual for your use and duplication). The four key parameters we need to place in our Remote I/O configuration table is in the lower right corner of the worksheet. You can determine the address values by using the memory map given at the end of Chapter 3, CPU Specifications and Operation. The program segment required to transfer our worksheet results to the Remote I/O configuration table is shown to the right. Remember to use the LDA or LD instructions appropriately. The next page covers the remainder of the required program to get this remote I/O link up and running. DL405 User Manual, 4th Edition, Rev. A 16 Total Output Points_____ DirectSOFT SP0 LDA O40403 OUT V37704 LD K16 OUT V37705 LDA O40502 OUT V37706 LD K16 OUT V37707 System Design and Configuration When configuring a Remote I/O channel for fewer than 7 slaves, we must fill the remainder of the table with zeros. This is necessary because the CPU will try to interpret any non-zero number as slave information. We continue our setup program from the previous page by adding a segment which fills the remainder of the table with zeros. The easiest way is the use the fill command as shown. The example to the right fills zeros for slave numbers 2--7, which do not exist in our example system (6 bases x 4 = 24 locations, = 18 hex). 4--17 DirectSOFT LD K18 LDA O37710 FILL K0 C740 SET On the last rung in the example program above, we set a special relay contact C740. This particular contact indicates to the CPU that the ladder program has just finished specifying a remote I/O system. At that moment the CPU begins remote I/O communications. Be sure to include this contact after any Remote I/O setup program. Remote I/O Test Program Now we can verify the remote I/O link and setup program operation. A simple quick check can be done with just one rung of ladder, shown to the right. It connects the first input of the remote base with the first output. After placing the PLC in RUN mode, we can go to the remote base and activate its first input. Then its first output should turn on. DirectSOFT X60 Y40 OUT System Design and Configuration DL405 User Manual, 4th Edtition, Rev. A 4--18 System Design and Configuration Network Connections to MODBUSR and DirectNET Configuring the CPU’s Comm Ports 430 440 450 This section describes how to configure the CPU’s built-in networking ports. for either MODBUS or DirectNET. This will allow you to connect the DL405 PLC system directly to MODBUS networks using the RTU protocol, or to other devices on a DirectNET network. MODBUS hosts system on the network must be capable of issuing the MODBUS commands to read or write the appropriate data. For details on the MODBUS protocol, please refer to the Gould MODBUS Protocol reference Guide (P1--MBUS--300 Rev. B). In the event a more recent version is available, check with your MODBUS supplier before ordering the documentation. For more details on DirectNET, order our DirectNET manual, part number DA--DNET--M. NOTE: For information about the MODBUS protocol see the Group Schneider website at: www.schneiderautomation.com. At the main menu, select Support/Services, Modbus Technical Manuals, PI--MBUS--300 Modbus Protocol Reference Guide or search for PIMBUS300. For more information about DirectNET protocol, order our DirectNET user manual, part number DA--DNET--M, or download it free from our website: www.automationdirect.com. Select Manuals/Docs > Online User Manuals > Misc. > DA--DNET--M. The DL430 and DL440 can be DirectNET slaves on port 1. Both the DL450’s Port 1 and Port 3 can operate as master or slave for both MODBUS and DirectNET. Port 1 has RS--232 and RS--422 signal levels available on separate pins, and Port 3 (DL450) uses RS--422 signal levels. Ports 1 and Port 3 on the DL450 share the 25-pin D-shell connector, as shown to the right. Connect one or both ports as shown below. Note that you cannot simultaneously use Port 1’s RS--232 signals and its RS--422 signals. System Design and Configuration Port 1 Port 3 DL430 DirectNET, N/A and slave only DL440 DirectNET or DirectNET or DL450 MODBUS, MODBUS, master/slave master/slave Port 3 Port 1 1 TXD RXD RTS CTS 0V RXD+ RXD-CTS+ TXD+ 14 TXD-RTS-RTS+ 0V CTS-TXD+ TXD-- 13 25 RXD+ RXD-- NOTE: The recommended cable for RS--232 or RS--422 is Belden 8102 or equivalent. DL405 User Manual, 4th Edition, Rev. A 4--19 System Design and Configuration You will need to determine whether the network connection is a 3-wire RS--232 type, or a 5-wire RS--422 type. Normally, we use RS--232 signals for shorter distances (15 meters max), for communications between just two devices. Use RS--422 signals for longer distances (1000 meters max.), and for multi-drop networks (from 2 to 248 devices). Be sure to use termination resistors at the both ends of RS--422 network wiring, matching the impedance rating of the cable (between 100 and 500 ohms). NOTE: If your DL405 is to be used as a MODBUS Master and the distance will be more than 1000 feet, you can use the MODBUS Network Master module, F4--MAS--MB, and use the RS--485 port. See the module on our website, www.automationdirect.com for more details. RS--422 Network Master RXD+ RXD-TXD+ TXD-Signal GND TXD RXD RS--232C Point-to-point Signal GND PORT 1 RS--232C PORT 1 RS--422 PORT 3 RS--422 2 3 4 5 7 14 TXD+ 16 TXD-9 RXD+ 10 RXD-18 RTS-19 RTS+ 11 CTS+ 23 CTS-7 0V 12 13 24 25 7 TXD RXD RTS CTS 0V TXD+ TXD-RXD+ RXD-0V RS--422 Network Slaves System Design and Configuration DL405 User Manual, 4th Edtition, Rev. A 4--20 System Design and Configuration MODBUS Port Configuration 430 440 450 In DirectSOFT, choose the PLC menu, then Setup > Secondary Comm Port. S Port: From the port number list box at the top, choose Port 1 or 3. S Protocol: Click the box to the left of MODBUS to select it (use AUX 56 on the HPP, and select MBUS). The dialog below will appear. 3 S S System Design and Configuration S S S S Timeout: amount of time the port will wait after it sends a message to get a response before logging an error. RTS on delay time: the amount of time the port waits to send a message after it’s ready to send. For port 1, it activates the RTS line before it begins transmitting (assuming CTS is already active). The port will not transmit if the CTS input is false. Station Number: For making the CPU port a MODBUSR master, choose “1”. The possible range for MODBUS slave numbers is from 1 to 247, but the DL450 network instructions will access only slaves 1 to 90. Each slave must have a unique number. At powerup, the port is automatically a slave, unless and until the DL450 executes ladder logic network instructions which use the port as a master. Thereafter, the port reverts back to slave mode until ladder logic uses the port again. Baud Rate: The available baud rates include 300, 600, 900, 2400, 4800, 9600, 19200, and 38400 baud. Choose a higher baud rate initially, reverting to lower baud rates if you experience data errors or noise problems on the network. Important: You must configure the baud rates of all devices on the network to the same value. Refer to the appropriate product manual for details. Stop Bits: Choose 1 or 2 stop bits for use in the protocol. Parity: Choose none, even, or odd parity for error checking. Then click the button indicated to send the Port configuration to the CPU, and click Close. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration DirectNET Port Configuration 430 440 450 4--21 In DirectSOFT, choose the PLC menu, then Setup > Secondary Comm Port. S Port: From the port number list box, choose Port 1 or 3 (DL450 only). S Protocol: Click the box to the left of DirectNET to select it (use AUX 56 on the HPP, then select DNET). The dialog below will appear. S S S S S S Then click the button indicated to send the Port configuration to the CPU, and click Close. DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration S Timeout: amount of time the port will wait after it sends a message to get a response before logging an error. RTS delay time: the amount of time the port waits to send a message after it’s ready to send. For port 1, it activates the RTS line before it begins transmitting (assuming CTS is already active). The port will not transmit if the CTS input is false. Station Number: For making the CPU port a DirectNET master, choose “1”. The allowable range for DIrectNET slaves is from 1 to 90 (each slave must have a unique number). At powerup, the port is automatically a slave, unless and until the DL450 executes ladder logic instructions which attempt to use the port as a master. Thereafter, the port reverts back to slave mode until ladder logic uses the port again. Baud Rate: The available baud rates include 300, 600, 900, 2400, 4800, 9600, 19200, and 38400 baud. Choose a higher baud rate initially, reverting to lower baud rates if you experience data errors or noise problems on the network. Important: You must configure the baud rates of all devices on the network to the same value. Stop Bits: Choose 1 or 2 stop bits for use in the protocol. Parity: Choose none, even, or odd parity for error checking. Format: Choose between hex or ASCII formats. 4--22 System Design and Configuration Network Slave Operation This section describes how other devices on a network can communicate with a CPU port that you have configured as a DirectNETslave or MODBUS slave (DL450). A MODBUS host must use the MODBUS RTU protocol to communicate with the DL450 as a slave. The host software must send a MODBUS function code and MODBUS address to specify a PLC memory location the DL450 comprehends. The DirectNET host just uses normal I/O addresses to access any DL405 CPU and system. No CPU ladder logic is required to support either MODBUS slave or DirectNET slave operation. MODBUS Function The MODBUS function code determines whether the access is a read or a write, and Codes Supported whether to access a single data point or a group of them. The DL450 supports the MODBUS function codes described below. 430 440 450 430 440 450 MODBUS Function Code 01 Read a group of coils Y, CR, T, CT, GY 02 Read a group of inputs X, SP, GX 05 (slave only) Set / Reset a single coil Y, CR, T, CT Set / Reset a group of coils Y, CR, T, CT 15 03, 04 Read a value from one or more registers V 06 (slave only) 16 MODBUS Data Types Supported Write a value into a single register V Write a value into a group of registers V The memory types in a DL405 system include X input, Y output, C control relay, V memory data registers, etc. MODBUS uses differently named data types. So, you will need to determine which MODBUS data type corresponds to any desired PLC memory location by using the cross-reference table below. DL450 Memory Type System Design and Configuration DL405 Data Types Available Function Quantity (Decimal) PLC Range (Octal) Corresponding MODBUS Data Type Rx Function Code Inputs (X) 1024 X0 -- X1777 Input 02 Global Inputs (GX) 1536 GX0 -- GX2777 Input 02 Special Relays (SP) 512 SP0 -- SP137 SP320 -- SP717 Input 02 Outputs (Y) 1024 Y0 -- Y1777 Coil 01 Global Outputs (GY) 1536 GY0 -- GY2777 Coil 01 Control Relays (CR) 2048 C0 -- C3777 Coil 01 Timer Contacts (T) 256 T0 -- T377 Coil 01 Counter Contacts (CT) 256 CT0 -- CT377 Coil 01 Stage Status Bits (S) 1024 S0 -- S1777 Coil 01 Timer Current Values (V) 256 V0 -- V377 Input Register 03 Counter Current Value (V) 256 V1000 -- V1377 Input Register 03 V--Memory, user data (V) 3072 12288 V1400 -- V7377 V10000 -- V37777 Holding Register 03 V700 -- V777 V7400 -- V7777 Holding Register 03 V--Memory, system (V) DL405 User Manual, 4th Edition, Rev. A 320 System Design and Configuration Determining the MODBUS Address 4--23 There are typically two ways that most host software conventions allow you to specify a PLC memory location. These are: S By specifying the MODBUS data type and address S By specifying a MODBUS address only. If Your Host Software Many host software packages allow you to specify the MODBUS data type and the Requires the Data MODBUS address that corresponds to the PLC memory location. This is the easiest Type and Address... method, but not all packages allow you to do it this way. The various MODBUS data types were presented earlier, but they have been included again in the following table. The actual equation used to calculate the address depends on the type of PLC data you are using. The PLC memory types are split into two categories for this purpose. S Discrete -- X, SP, Y, CR, S, T, C (contacts) S Word -- V, Timer current value, Counter current value In either case, you basically just convert the PLC octal address to decimal and add the appropriate MODBUS address (if required). The table below shows the exact equation used for each group of data. DL450 Memory Type QTY (Dec.) For Discrete Data Types .... Convert PLC Addr. to Dec. Inputs (X) 1024 Special Relays (SP) 512 Outputs (Y) MODBUS Address Range (Decimal) PLC Range (Octal) + Start of Range MODBUS Data Type + Data Type -- X1777 2048 -- 3071 Input SP0 SP320 --- SP137 SP717 3072 3280 --- 3167 3535 Input 1024 Y0 -- Y1777 2048 -- 3071 Coil Control Relays (CR) 2048 C0 -- C3777 3072 -- 5119 Coil Timer Contacts (T) 256 T0 -- T377 6144 -- 6399 Coil Counter Contacts (CT) 256 CT0 -- CT377 6400 -- 6655 Coil Stage Status Bits (S) 1024 S0 -- S1777 5120 -- 6143 Coil Global Inputs (GX) * 1536 GX0 -- GX2777 0 -- 1535 Input Global Outputs (GY) * 1536 GY0 -- GY2777 0 -- 1535 Coil For Word Data Types .... Timer Current Values (V) Convert PLC Addr. to Dec. 256 V0 -- V377 Counter Current Values (V) 256 V1000 -- V--Memory, user data (V) 3072 12288 V--Memory, system (V) 320 + Data Type 0 -- 255 Input Register V1377 512 -- 767 Input Register V1400 -V10000 -- V7377 V37777 768 4096 --- 3839 16383 Holding Register V700 V7400 V777 V7777 448 3480 --- 768 3735 Holding Register --- * Note: The total of GX and GY global I/O points cannot exceed 1536 points. DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration X0 4--24 System Design and Configuration The following examples show how to generate the MODBUS address and data type for hosts which require this format. Example 1: V2100 Find the MODBUS address for User V location V2100. 1. Find V--memory in the table. 2. Convert V2100 into decimal (1088). 3. Use the MODBUS data type from the table. V--Memory, user data (V) Example 2: Y20 System Design and Configuration V1400 -V7377 V10000--V37777 1024 Y0 -- Y1777 Find the MODBUS address to obtain the current value from Timer T10. 1. Find Timer Current Values in the table. 2. Convert T10 into decimal (8). 3. Use the MODBUS data type from the table. Timer Current Values (V) Example 4: C54 V2100 = 1088 decimal 1088 + Hold. Reg. = Holding Reg. 1088 768 4096 --- 3839 16383 Holding Register Find the MODBUS address for output Y20. PLC Addr. (Dec) + Start Addr. + Data Type 1. Find Y outputs in the table. Y20 = 16 decimal 2. Convert Y20 into decimal (16). 16 + 2048 + Coil = Coil 2064 3. Add the starting address for the range (2048). 4. Use the MODBUS data type from the table. Outputs (Y) Example 3: T10 Current Value 3072 12288 PLC Address (Dec.) + Data Type 256 V0 -- 2048 -- 3071 Coil PLC Address (Dec.) + Data Type T10 = 8 decimal 8 + Input Reg. = Input Reg. 8 V377 0 -- 255 Input Register Find the MODBUS address for Control Relay PLC Addr. (Dec) + Start Addr. +Data Type C54. C54 = 44 decimal 1. Find Control Relays in the table. 44 + 3072 + Coil = Coil 3116 2. Convert C54 into decimal (44). 3. Add the starting address for the range (3072). 4. Use the MODBUS data type from the table. Control Relays (CR) DL405 User Manual, 4th Edition, Rev. A 2048 C0 -- C3777 3072 -- 5119 Coil System Design and Configuration If Your MODBUS Host Software Requires an Address ONLY 4--25 Some host software does not allow you to specify the MODBUS data type and address. Instead, you specify an address only. This method requires another step to determine the address, but it’s still fairly simple. Basically, MODBUS also separates the data types by address ranges as well. So this means an address alone can actually describe the type of data and location. This is often referred to as “adding the offset”. One important thing to remember here is that two different addressing modes may be available in your host software package. These are: S 484 Mode S 584/984 Mode We recommend that you use the 584/984 addressing mode if your host software allows you to choose. This is because the 584/984 mode allows access to a higher number of memory locations within each data type. If your software only supports 484 mode, then there may be some PLC memory locations that will be unavailable. The actual equation used to calculate the address depends on the type of PLC data you are using. The PLC memory types are split into two categories for this purpose. S Discrete -- X, GX, SP, Y, CR, S, T (contacts), C (contacts) S Word -- V, Timer current value, Counter current value In either case, you basically just convert the PLC octal address to decimal and add the appropriate MODBUS addresses (as required). The table below shows the exact equation used for each group of data. DISCRETE DATA TYPES Memory Type Global Inputs (GX) Inputs (X) PLC Range (Octal) GX0 -- GX1746 GX1747 -- GX3777 Address (484 Mode) 1001 -- 1999 Address (584/984 Mode) Data Type 10001 -- 10999 Input ------ 11000 -- 12048 Input -- X1777 ------ 12049 -- 13072 Input Special Relays (SP) SP0 -- SP777 ------ 13073 -- 13584 Input Global Outputs (GY) GY0 -- GY3777 Outputs (Y) Y0 -- Control Relays (CR) C0 Timer Contacts (T) Counter Contacts (CT) Stage Status Bits (S) 1 -- 2048 1 -- 2048 Output Y1777 2049 -- 3072 2049 -- 3072 Output -- C3777 3073 -- 5120 3073 -- 5120 Output T0 -- T377 6145 -- 6400 6145 -- 6400 Output CT0 -- CT377 6401 -- 6656 6401 -- 6656 Output S0 -- S1777 5121 -- 6144 5121 -- 6144 Output DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration X0 4--26 System Design and Configuration WORD DATA TYPES PLC Range (Octal) Registers V--memory (Timers) Input/Holding (484 Mode)* Input/Holding (585/984 Mode)* V0 -- V377 3001/4001 30001/40001 V--memory (Counters) V1000 -- V1177 3513/4513 30513/40513 V--memory (Data Words) V1200 -- V1377 3641/4641 30641/40641 V--memory (Data Words) V1400 -- V1746 3769/4769 30769/40769 V--memory (Data Words) V1747 -- V1777 ------ 31000/41000 V--memory (Data Words) V2000 -- V7377 ------ 41025 V--memory (Data Words) V10000 -- V17777 ------ 44097 *MODBUS: Function 04 (New feature) The DL450 will support function 04 read input register (Address 30001). To use function 04, put the number ’4’ into the most significant position (4xxx). Four digits must be entered for the instruction to work properly with this mode. LD K101 LD K4128 LDA O4000 The Maximum constant possible is 4128. This is due to the 128 maximum number of Bytes that the RX/WX instruction can allow. The value of 4 in the most significant position of the word will cause the RX to use function 04 (30001 range). System Design and Configuration RX Y0 1. Refer to the Memory Mapping section of this manual for the correct memory mapping size. Some of the addresses shown above might not pertain to your CPU. 2. For an automated MODBUS/Koyo address conversion utility, download the file modbus_conversion.xls from our website, www.automationdirect.com. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration 4--27 Example 1: V2100 584/984 Mode Find the MODBUS address for User V location V2100. 1. Find V--memory in the table. 2. Convert V2100 into decimal (1088). 3. Add the MODBUS starting address for the mode (40001). Example 2: Y20 584/984 Mode Find the MODBUS address for output Y20. PLC Addr. (Dec) + Start Address + Mode 1. Find Y outputs in the table. Y20 = 16 decimal 2. Convert Y20 into decimal (16). 16 + 2048 + 1 = 2065 3. Add the starting address for the range (2048). 4. Add the MODBUS address for the mode (1). Example 3: T10 Current Value 484 Mode Find the MODBUS address to obtain the current value from Timer T10. 1. Find Timer Current Values in the table. 2. Convert T10 into decimal (8). 3. Add the MODBUS starting address for the mode (3001). Example 4: C54 584/984 Mode Find the MODBUS address for Control Relay PLC Addr. (Dec) + Start Address + Mode C54. C54 = 44 decimal 1. Find Control Relays in the table. 44 + 3072 + 1 = 3117 2. Convert C54 into decimal (44). 3. Add the starting address for the range (3072). 4. Add the MODBUS address for the mode (1). PLC Address (Dec.) + Mode Address V2100 = 1088 decimal 1088 + 40001 = 41089 PLC Address (Dec.) + Mode Address TA10 = 8 decimal 8 + 3001 = 3009 System Design and Configuration DL405 User Manual, 4th Edtition, Rev. A 4--28 System Design and Configuration Network Master Operation 430 440 450 This section describes how the DL450 can communicate on a MODBUS or DirectNET network as a master. For MODBUS networks, it uses the MODBUS RTU protocol, which must be interpreted by all the slaves on the network. Since MODBUS and DirectNET are master / slave networks, the master station must initiate requests for network data transfers. This section teaches you how to design the required ladder logic for network master operation. Master Slave #1 Slave #2 Slave #3 System Design and Configuration MODBUS RTU Protocol, or DirectNET When using the DL450 CPU as the master station, you use simple RLL instructions to initiate the requests. The WX instruction initiates network write operations, and the RX instruction initiates network read operations. Before executing either the WX or RX commands, we will need to load data related to the read or write operation onto the CPU’s accumulator stack. When the WX or RX instruction executes, it uses the information on the stack combined with data in the instruction box to completely define the task, which goes to the port. It’s possible to use both Port 1 and Port 3 for either MODBUS or DirectNET, and to use either or both as masters. You must tell the WX and RX instructions the intended port for each communications transaction. Master Slave WX (write) RX (read) Network Network 1 Network 2 To summarize, the RLL instructions identify the following items. 1. Port number on the master (Port 1 or 3), and the slave station address. (LD instruction) 2. Amount of data (in bytes) you want to transfer. (LD instruction) 3. Area of memory to be used by the master. (LDA instruction) 4. Area of CPU V-memory to be used in communication with the slave, and whether it is a write or read operation. (WX or RX instruction) 5. Interlocks for communication timing for multiple WX and RX routines. DL405 User Manual, 4th Edition, Rev. A System Design and Configuration Step 1: Identify Master Port # and Slave # Step 2: Load Number of Bytes to Transfer The first Load (LD) instruction identifies the communications port number on the network master (DL450) and the address of the slave station. This instruction can address up to 90 MODBUS slaves, or 90 DirectNET slaves. The format of the word is shown to the right. The “F” in the upper nibble tells the CPU the port is internal to the CPU (and not in a slot in the base). The second nibble indicates the port number, 1 or 3. The lower byte contains the slave address number in BCD (01 to 90). The second Load (LD) instruction determines the number of bytes which will be transferred between the master and slave in the subsequent WX or RX instruction. The value to be loaded is in BCD format (decimal), from 1 to 128 bytes. F 1 0 4--29 1 Slave address (BCD) Port number (BCD) Internal port (hex) LD KF101 1 2 8 (BCD) # of bytes to transfer LD K128 The number of bytes specified also depends on the type of data you want to obtain. For example, the DL405 Input points can be accessed by V-memory locations or as X input locations. However, if you only want X0 -- X27, you’ll have to use the X input data type because the V-memory locations can only be accessed in 2-byte increments. The following table shows the byte ranges for the various types of DirectLOGIC™ products. DL 205 / 405 Memory Bytes V--memory T / C current value 16 16 2 2 Inputs (X, GX, SP) 8 1 Outputs (Y, C, Stage, T/C bits) 8 1 Scratch Pad Memory 8 1 Diagnostic Status 8 1 Bits per unit Bytes Data registers T / C accumulator 8 16 1 2 I/O, internal relays, shift register bits, T/C bits, stage bits 1 1 Scratch Pad Memory 8 2 Diagnostic Status(5 word R/W) 16 10 DL305 Memory DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration Bits per unit 4--30 System Design and Configuration The third instruction in the RX or WX sequence is a Load Address (LDA) instruction. Its purpose is to load the starting address of the memory area to be transferred. Entered as an octal number, the LDA instruction converts it to hex and places the result in the accumulator. For a WX instruction, the DL450 CPU sends the number of bytes previously specified from its memory area beginning at the LDA address specified. For an RX instruction, the DL450 CPU reads the number of bytes previously specified from the slave, placing the received data into its memory area beginning at the LDA address specified. Step 3: Specify Master Memory Area 4 0 6 0 0 (octal) Starting address of master transfer area LDA O40600 MSB V40600 LSB 15 0 MSB V40601 LSB 15 0 NOTE: Since V--memory words are always 16 bits, you may not always use the whole word. For example, if you only specify 3 bytes and you are reading Y outputs from the slave, you will only get 24 bits of data. In this case, only the 8 least significant bits of the last word location will be modified. The remaining 8 bits are not affected. The last instruction in our sequence is the WX or RX instruction itself. Use WX to write to the slave, and RX to read from the slave. All four of our instructions are shown to the right. In the last instruction, you must specify the starting address and a valid data type for the slave. The RX instruction reads data from the slave starting at the address specified. The WX instruction writes data to the slave starting at the address specified. System Design and Configuration Step 4: Specify Slave Memory Area S S S SP112 LD KF101 LD K128 LDA O40600 RX Y0 DirectNET slaves -- specify the same address in the WX and RX instruction as the slave’s native I/O address MODBUS DL405 or DL205 slaves -- specify the same address in the WX and RX instruction as the slave’s native I/O address MODBUS 305 slaves -- use the following table to convert DL305 addresses to MODBUS addresses DL305 Series CPU Memory Type--to--DL405 Series CPU Memory PLC Memory type 305 base address 405 base addr. PLC Memory Type 305 base address 405 base addr. TMR/CNT Current Values R600 V0 TMR/CNT Status Bits CT600 GY600 I/O Points IO 000 GY0 Control Relays CR160 GY160 Data Registers R401, R400 V100 Shift Registers SR400 GY400 Stage Status Bits (D3--330P only) S0 GY200 DL405 User Manual, 4th Edition, Rev. A 4--31 System Design and Configuration Communications from a Ladder Program In some applications, the DL450 CPU as a network master will communicate only periodically to slaves(s) on the network. However, most applications will probably want to make a “continuous” update of memory areas from a slave to the master. This normally means starting the task on each PLC SCAN. However, a single WX or RX network communication will probably last longer than one PLC scan time. And we must wait before executing another RX or WX until the port has finished transmitting the previous WX or RX data. Port Communication Error SP113 Y1 SET SP112 LD KF101 LD K0003 Port Busy LDA O40600 RX Y0 Each port which can be a master has two Special Relay contacts associated with it (see Appendix D for comm port special relays).One indicates “Port busy”, and the other indicates ”Port Communication Error”. The example above shows the use of these contacts for a network master that only reads a device (RX). The Port Busy contact ensures one network transaction finishes before we begin another. Use of the communication error SP relay is optional. If used, be sure to place it at the beginning of the communication routines, because a comm error relay is always reset (turned off) whenever an RX or WX instruction using the same port executes. Multiple Read and Write Interlocks Interlocking Relay SP112 C100 LD KF101 LD K0003 LDA O40600 Interlocking Relay SP112 C100 RX Y0 C100 SET LD KF101 LD K0003 LDA O40400 WX Y0 C100 RST DL405 User Manual, 4th Edtition, Rev. A System Design and Configuration If you’re using multiple reads and writes in the RLL program, you have to interlock the routines to make sure all the routines are executed. If you don’t use the interlocks, then the CPU will only execute the first routine. This is because each port can only handle one transaction at a time. In the example to the right, after the RX instruction is executed, C0 is set. When the port has finished the communication task, the second routine is executed and C0 is reset. If you’re using RLL PLUS Stage Programing, you can just put each routine in a separate program stage to ensure proper execution. In most cases, RLL PLUS is a much more efficient way to create an automation program. The DirectNET manual provides a master/slave example with both RLL and Stage program descriptions (they are easily adapted for use with MODBUS).
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project