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Chapter 6. COMMREQ/Data_Init_Comm Programming
4)
Check the status of the initiated COMMREQ task. COMMREQs should be executed
sequentially. The application program should check that the status of the previous
COMMREQ to the targeted PROFINET Controller is complete before sending it another one.
Failure to do this may result in improper operation of the PROFINET Controller.
6.3 COMMREQ Command Block Format
The first step in programming communications requests is to set up the contents of the
COMMREQ instruction. This can be done using Block Moves or similar program instructions, as
shown later in this chapter.
Command Block
Data is placed in adjacent locations in CPU memory to form a Command Block, per the format
shown below:
The length of the Command Block depends on the type of COMMREQ being sent. Seventy
words is the maximum and is used only for a COMMREQ that transfers a 128–byte datagram.
Most Command Blocks are much shorter. The table in Section 6.3.3 gives an overview of the
contents of each type of COMMREQ that may be sent to a PROFINET Controller for transfer to
a Genius Gateway.
46 Public
PACSystems RX3i Genius Communications Gateway User Manual
CPU Memory
Location
Data Field
address
"Data Block" Length
address + 1
Wait/No Wait Flag
address + 2
Status Pointer Memory Type
address + 3
Status Pointer Offset
address + 4
Idle Timeout Value (ms)
address + 5
Max. Communication Time (ms)
address + 6 to
Data Block
address + 78
⇐
Edit content of COMMREQ
Value
Always 0
Always 0
Always 0
Application Program
GFK-2892B
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