Rockwell Automation 5370 CVIM Communications Manual - Manual (Page 100)

Chapter 5
Using the RS–232 Ports
5–30
Use the deactivate force command to return outputs on the 1771–JMB local
I/O board to the CVIM module assigned functions. The deactivate forces
command is:
If the BCC is not valid, the CVIM module will respond with a DLE NAK
and the command will not be executed.
If the BCC is valid, the CVIM module will respond with a DLE ACK. Then
the CVIM module will validate the command structure. If the command is
valid, the CVIM module will execute the command and return the data. If the
command structure is invalid, the CVIM module will not execute the
command or respond.
Use the echo command to check the communications link. This command
will return the same same string of characters that are sent out with the
command. This command has the following structure:
01 00 n times Data
Where n times specifies the number of times the CVIM module will echo the
data field back to the host device. There is no object associated with this
command. The command is valid at any time.
For example:
01
This example will cause the CVIM module to return the string:
DLE ACK DLE STX 1234512345123451234512345 DLE ETX BCC
If the BCC is not valid, the CVIM module will respond with a DLE NAK
and the command will not be executed.
If the BCC is valid, the CVIM module will respond with a DLE ACK. Then
the CVIM module will validate the command structure. If the command is
valid, the CVIM module will execute the command and echo the data. If the
command structure is invalid, the CVIM module will not execute the
command or respond.
Deactivate Forces
Echoing Data