Festo CMXR-C1, Description

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5. PLC interface MCP 2
36 Festo GDCP-CMXR-F-EN 0909a
5.2 Function of the PLC interface MCP2
The command interface MCP2 can be used to exchange acyclic data using the multi-axis
controller. The function of the command interface is not dependent on the control
sovereignty. This means that even if the robot is controlled via the teach pendant, it is
possible to exchange data via field bus.
The command interface has a width of 52 byte, which is, in turn, divided into 4-byte
headers and 48-byte parameters. The interface header is needed for the control of the
transmission and the parameters contain the transmission data.
MCP2 header
The MCP2 header consists of 4-byte I/O data respectively.
CREG, SREG Control or status register (1-byte)
CODE Function code
SUBCODE Subcode of the function code
INDEX Index of the function code
Command sequence
Before a command or job can be executed, the function must be specified in the header.
A job always consists of CODE, SUBCODE and INDEX; should one of them not be needed,
then a 0 must be transferred there.
The command is executed using EXECUTE in the CREG byte. The interface always answers
with DONE = TRUE; should an error have occurred during the transmission, then the
controller also replies with ERROR and returns a 6-bit error code RETVAL in the SREG byte.
The transferred parameters are only valid if the interface reports back DONE = TRUE. In
the event of an error, the error code RETVAL is also only valid if the ERROR and DONE bits
report TRUE.