Operating instructions

PTQ-MCM ♦ Quantum / Unity Platform Modifying the Configuration File
Modbus Communication Module
Page 70 of 139 ProSoft Technology, Inc.
April 29, 2008
Retry Count
Retry Count : 0 #Retry count for failed request (Master)
This parameter specifies the number of times a command will be retried if it fails.
If the master port does not receive a response after the last retry, the slave
device's communication will be suspended on the port for Error Delay Counter
scans.
Error Delay Counter
0 to 65535
This parameter specifies the number of polls to skip on the slave before trying to
re-establish communications. After the slave fails to respond, the master will skip
commands to be sent to the slave the number of times entered in this parameter.
6.2.4 [Modbus Port 1 Commands]
[Modbus Port 1 Commands]
# Internal Poll Reg Swap Node Modbus MB Address
# Enable Address Interval Count Code Address Func in Device
START
1 0 0 10 0 255 16 100 #
1 0 0 10 1 255 16 110 #
1 0 0 10 2 255 16 120 #
1 0 0 10 3 255 16 130 #
END
You should configure the following parameters for each command:
Parameter Description
Enable
This parameter defines how the command will be sent. The following codes
are valid:
0: Disabled
Disables the command. This command could still be activated from the
processor using the Command Control special block (requires backplane
command code 3)
1: Continuous
The command will be issued with a frequency determined by the poll interval
parameter that is used to define minimum delays between consecutive
commands.
2: Conditional
The conditional command is sent when the source data changes. It only
applies to modbus write commands (modbus functions 5,6, 15 and 16)
Internal Address
Configure the PTQ-MCM database address associated with the modbus
command.
For a read command: this is the database address where the data read from
the slave device will be copied to.
For a write command: this is the database address where the data written to
the slave device will be copied from.
For bit commands (for example: 1, 2, 5 and 15) the module expects this value
to represent the bit-address in the database. For example, a value of 100
would actually configure the Internal Address as BIT 100.
For word commands (for example: 3, 4, 6 and 16) the module expects this
value to represent the word-address in the database. For example, a value of
100 would actually configure the Internal Address as WORD 100 (1 word = 2
bytes).