ProSoft Technology PTQ-PDPMV1 - Manual (Page 128)

Configuring the Processor with Concept 2.6 PTQ-PDPMV1 ♦ Quantum Platform
User Manual PROFIBUS DP Master Network Interface Module for Quantum
Page 128 of 306 ProSoft Technology, Inc.
August 12, 2014
The following illustration shows an example of two registers that indicate whether
the first 16 devices are currently configured
(PTQPDPMV1_In_Stat.ConfigList[0]), and if these devices are in data exchange
mode (PTQPDPMV1_In_Stat.TransferStat[0]). The following illustration shows an
example in which slave 13 is configured and in data exchange mode.
Note: The actual variable name will depend on the project name you have selected in PCB
(PTQPDPMV1 is default).
4.10.3 Configuration Validation & SETCRC Function Block
The configuration validation functionality prevents the module from causing
unexpected results after it receives a new configuration (for example, if it
receives a configuration that should have been downloaded to a different
module). The PTQ-PDPMV1 module constantly transfers two CRC values to the
processor (as part of the input status data) which are calculated based on its
current configuration. The processor must copy back the same CRC values to
the module (as part of the output status data). If the CRC values are not
synchronized, the module will be switched to STOP mode and the CFG ERR
LED will be illuminated. If the CFG ERR LED is OFF it means that the CRC
values are synchronized. While the module is in STOP mode, there will be no
data exchange with the configured PROFIBUS slaves.
The SETCRC function block is presented in this procedure for convenience
purposes to get your PTQ-PDPMV1 module up and running. The SETCRC
function block automatically updates the CRC through the following lines of
structured text code:
StatOut.PROFIBUSCRC :=StatIn.PROFIBUSCRC;
StatOut.ModuleCRC :=StatIn.ModuleCRC;
This procedure suggests the use of the SETCRC function block in order to avoid
the module being set to STOP mode during successive configuration changes
(these changes typically occur during the initial setup steps). However, please
note that the SETCRC function block also prevents the module from supporting
the configuration validation functionality, because the CRC values will always be
synchronized even if an unexpected download occurs.
After the module is configured and the CRC values are synchronized, the
SETCRC function block can be disabled (for applications that require
configuration validation).
To disable the SETCRC function block, follow these steps:
1 Double-click the SETCRC F UNCTION B LOCK at the FBD section