ICS Regent ® PD-6041 Communications Package for W INTERPRET Guarded Peer-Link Communications (T3831) Issue 1, March, 06 The WINTERPRET Communications Package is an add-in software package that allows you to configure Guarded Peer-Link communications for interconnected Regent systems. Using Guarded Peer-Link, multiple Regent systems can transfer safety-critical data between each other for distributed safety interlocking within a plant.
Communications Package for W INTERPRET (T3831) Software Installation The Communications package is installed on the PC running the WINTERPRET application software. The WINTERPRET base package provides the necessary installation software to install this add-in communications package. The communications package should be installed at the same time or after you have installed the WINTERPRET base package.
Communications Package for W INTERPRET (T3831) communications see Configuring the Guarded Peer-Link, starting on page 11. Guarded Peer-Link Operation Guarded Peer-Link communications allow multiple Regents to send and receive data over a bussed serial communications network. This multidrop network can be made redundant by using up to five separate multidrop legs, each connected to serial ports on the Regent communications modules. An example is shown in Figure 1. Figure 1.
Communications Package for W INTERPRET (T3831) Theory of Operation Each leg of the GPL network uses a bussed multidrop RS-485 communication link for exchanging data between up to 31 Regents. When loaded and operating, the GPL communications activity on each leg sequences through polling commands and broadcast responses as shown in Figure 2. The completion of this sequence for each Regent on the network makes up a GPL communications cycle.
Communications Package for W INTERPRET (T3831) Figure 3. Structure of the GPL Input Templates. The input templates allow the Regent to understand the data format of GPL variables from each Regent’s data packet and where to copy the needed variables from the input buffers into this Regent’s I/O and shared variables. In addition, the input template contains initial and final values for each variable (as configured in the I/O or shared variable editors).
Communications Package for W INTERPRET (T3831) Input Data Buffers Each Regent connected to a GPL network with “L” legs has 2*L input data buffers for each node on the network (including itself). For example a GPL network with two legs (dual redundant) has 4 input data buffers for each node (two for each leg). Each of these data buffers is the size of the GPL data packet from the associated node.
Communications Package for W INTERPRET (T3831) recent to transfer the input GPL variables into the Regent’s shared variables and I/O memory areas (as defined by the input templates). Output Template The Output Template is used to identify which variables in the Regent are configured as GPL variables that this Regent provides to the GPL network. Figure 5 illustrates the structure of the GPL output template for an individual Regent configured for Guarded Peer-Link communications. Figure 5.
Communications Package for W INTERPRET (T3831) Figure 6. Structure of the GPL Output Data Buffers. Each buffer is the size of the GPL data packet that this Regent provides to the network. At the end of each application program scan, the values of the variables configured for GPL are copied into the primary output data buffer.
Communications Package for W INTERPRET (T3831) templates in each Regent provide a complete definition of the entire GPL network configuration. When the GPL communications are active (see Connect Network, starting on page 22) each Regent monitors the activities of the GPL network for the types of errors listed in Table 1. A brief explanation accompanies each type of error. Table 1. Guarded Peer-Link Communications Errors.
Communications Package for W INTERPRET (T3831) GPL communications. A brief description of each of these variables is provided in Table 2. Table 2. GPL System Variables. 10 Variable Name Description GPLPxMASTER Port x is configured as a GPL Net Master Port — x is the port number (2 through 5). This bit turns on after loading the Regent serial ports definition. GPLMSTRSCAN The GPL master is scanning.
Communications Package for W INTERPRET (T3831) Configuring the Guarded Peer-Link Configuration Planning The Guarded Peer-Link Definitions Dialog is accessed from the Project Selector Window’s Definitions Menu. Before you use this command you should perform the following activities. 1) Define all Projects Each Regent to be connected using Guarded Peer-Link communications must be defined as a project using WINTERPRET.
Communications Package for W INTERPRET (T3831) Configuring the Regent Serial Ports for GPL Communications In each Regent project, use the Serial Ports command from the Project Editor’s Definitions Menu to define the serial ports used for GPL communications. An example of the Serial Ports dialog is shown in Figure 7. Figure 7. Defining GPL Ports in the Serial Ports Dialog. In this example, two ports are configured for GPL communications indicating that the GPL network uses two legs for redundancy.
Communications Package for W INTERPRET (T3831) Table 3. Example of Serial Port Settings for Four Regents. Port # Node # Port Type Baud Rate Data Format Network Leg Regent 1 2 1 Net Master 19.2K 8+1+Odd 1 4 1 Net Slave 19.2K 8+1+Odd 2 Regent 2 2 2 Net Slave 19.2K 8+1+Odd 1 4 2 Net Slave 19.2K 8+1+Odd 2 Regent 3 4 3 Net Slave 19.2K 8+1+Odd 1 6 3 Net Slave 19.2K 8+1+Odd 2 Regent 4 3 4 Net Slave 19.2K 8+1+Odd 1 5 4 Net Master 19.
Communications Package for W INTERPRET (T3831) Table 4. Example of Variable Definitions. GPL Output Variables Regent 1 Regent 2 Regent 3 Regent 4 LS101_R1 PT219_R2 PT308_R3 [none]3 XV118_R1 LT342_R3 LT172_R1 LT356_R3 PB100_R1 GPL Input Variables PT219_R2 PB100_R1 PT308_R3 XV118_R1 [none]2 LT172_R1 LT342_R3 LT356_R3 PB100_R1 Notes: 1) Choose a format for the tag names that you will use for GPL variables. For example, the last three characters of each tag name (e.g.
Communications Package for W INTERPRET (T3831) values are used by the GPL configuration when building the input data templates for each Regent. The initial value is used after a Regent warm starts until a valid data value is received by the GPL communications. If no initial value is defined, the variable will remain in its last state. The final value is used if the GPL communications times out and fresh data from the providing Regent is not received over any of the legs of the GPL network.
Communications Package for W INTERPRET (T3831) variable’s description. Configuring the Guarded Peer-Link is a three step process. Step 1: Select the projects that will participate in the GPL communications. Use the Projects button to open a dialog to select the participating projects. Step 2: Define the GPL variables. Use the Add, Edit and Delete Buttons to enter, change or remove a definition from the GPL variables list.
Communications Package for W INTERPRET (T3831) include it in GPL communications. Choose Exclude to remove the asterisk to exclude the project from GPL communications. When you are through choose OK to save your selections or Cancel to abandon any changes you have made to the participating projects list. After you choose OK or Cancel, the Guarded Peer-Link Participating Projects dialog closes and you return to the Guarded Peer-Link Configuration dialog.
Communications Package for W INTERPRET (T3831) Edit If you wish to change the definition of an existing GPL variable, select the variable using the mouse or keyboard and choose Edit. You would need to use edit if you entered the wrong name of a variable, or selected the wrong providing project. In the Edit Network Variable dialog, change the variable name or Providing Project as required.
Communications Package for W INTERPRET (T3831) 4) Each variable provided by a particular project is defined for that project (in its I/O or shared variable definitions). The compiler uses the list of GPL output variables to look for identically named variables in each of the other participating projects. When an identical name is found, the compiler checks that the variable is a similar data type (e.g. bit, word, or floating point) and can be written (e.g.
Communications Package for W INTERPRET (T3831) coordinated for each GPL leg by the Network Master for the associated leg (the Regent configured as Net Master). Figure 11. GPL Communications Wiring Diagram. Cable drops at Regents should be avoided or at least kept to a minimum (less than 3 feet). The cable shield should be maintained throughout the network and connected to a Metal connector hood at one node only (preferably the Net Master of the associated network leg).
Communications Package for W INTERPRET (T3831) Loading, Connecting and Starting the Guarded Peer-Link WINTERPRET provides commands to Load, Connect and Start the Guarded Peer-Link Network functions in the Regent. These commands are performed from the Execution Controller Window’s Network Menu. The Load Network and Connect Network commands must be performed on each Regent participating in the GPL communications.
Communications Package for W INTERPRET (T3831) When the Load Network command is completed, the system variables GPLINTEMP and GPLOUTTEMP will be on, indicating the GPL input and output templates have been loaded. Unload Network The Unload Network command deletes the GPL configuration from the Regent. This command cannot be used while the network is active (see Connect Network below).
Communications Package for W INTERPRET (T3831) Table 6. Commands Not Allowed While Network is Active.
Communications Package for W INTERPRET (T3831) After the Start Network command is performed, the Regent will begin issuing poll commands over the Net Master port to each Regent on the GPL communications network. When a Net Master has been started, and all other Regents are connected, The GPL should be fully functional (ignoring any hardware, cabling or configuration error problems). When a GPL Net Master is scanning, the system variable GPLMSTRSCAN is on in the Regent that has the Net Master port.
Communications Package for W INTERPRET (T3831) In a GPL network with one leg, stopping the Net Master stops all GPL communications activities. In a GPL network with two or more redundant legs, stopping one Net Master only stops the GPL communications for a single network leg. The other network legs should remain operational because they are managed by a different Regent node. The Regent that has been stopped only stops performing the Net Master polling for its associated network leg.
Communications Package for W INTERPRET (T3831) Figure 12. GPL Cycle Time vs. Amount of GPL Data.
Communications Package for W INTERPRET (T3831) Table 7. Example of GPL Data Configuration. Type of Variable Regent 1 Regent 2 Regent 3 Regent 4 Totals Bit Data 50 100 60 320 530 Word Data 10 42 15 65 132 FP Data 0 0 10 20 30 Applying the above equation to this configuration yields a total GPL data size of 914 bytes. Using this total GPL data size in the graph in Figure 12, indicates that the approximate GPL cycle time would be 1.05 seconds.
Communications Package for W INTERPRET (T3831) Figure 13. Application Scan Time Increase by GPL Communications. For example, assume the same GPL configuration shown in Table 7 where the total amount of GPL data is 914 bytes.
Communications Package for W INTERPRET (T3831) pack the bit type variables in each Regent into word type variables (using the Block Move instruction in ladder logic) then we could transfer 16 bits of data in only 2 bytes of GPL word data instead of 16 bytes of GPL bit data. In each Regent that receives the GPL data, the word data would be unpacked into individual shared control relays (again, using the Block Move instruction in ladder logic).
Communications Package for W INTERPRET (T3831) Troubleshooting the Guarded Peer-Link GPL Status Information After you use the Load, Connect and Start Network commands of WINTERPRET to activate the GPL operations in the Regent systems, each Regent performs diagnostics on the GPL communications. Make sure that you follow the steps outlined in the Loading, Connecting and Starting the Guarded Peer-Link, starting on page 21.
Communications Package for W INTERPRET (T3831) one can easily isolate the GPL fault to a particular leg of the GPL network. Third, a local fault bit named GPLFLTLOCAL will turn on if the Regent detects that the fault is caused locally by one of its own communications modules. Depending on the type of communications module failure and the function of the port (i.e. Net Master or Net Slave) the Regent may not always be able to determine that its local communications module is the source of the fault.
Communications Package for W INTERPRET (T3831) side of the cable fault will not show any transmit or receive activity. Check each Regent to see that it transmits its packet regularly on the effected leg of the network. If a transmit LED never turns on, but the receive LED does, then this communications module may be faulty (receiver fault). This Regent would not receive a poll command and so would not ever transmit its packet on this leg of the network.
