1031
Network Instructions
Section 3-25
Communications Flags
The operation of the communications flags is outlined below.
• The Communications Port Enabled Flag is reset to 0 when communica-
tions are in progress and set to 1 when communications are completed
(normally or not).
• The status of the Communications Port Error Flag is maintained until the
next time that data is transmitted or received.
• The Communications Port Error Flag will be reset to 0 the next time that
data is transmitted or received, even if there was an error in the previous
operation.
About Communications
Port Numbers
There are 8 logical communications ports provided, so 8 communications
instructions can be executed simultaneously. Only one instruction can be exe-
cuted at a time for each communications port. Exclusive control must be used
when more than 8 instructions are executed.
These 8 communications port numbers are shared by the network instructions
(SEND(090), RECV(098), and CMND(490)), the serial communications
instructions (TXDU(256) and RXDU(255)), and the PROTOCOL MACRO
instruction (PMCR(260)). Be sure not to specify the same port number on two
instructions at the same time.
0204
Busy
Communications Port
Enabled Flag
Network instruction
(SEND, RECV, or CMND)
Communications Port
Error Flag
Communications Port
Completion Code
Instruction 1
executing
Previous
completion
0000 (Normal
completion)
Instruction 2
executing
Instruction 3
executing
0000 (Normal completion)
Controller Link Unit,
Ethernet Unit, or Serial
Communications Unit
Port
CPU Unit
Instruction 1
Instruction 2
Instruction 3
Instruction 4
Instruction 5
Instruction 6
Instruction 7
Instruction 8
Summary of Contents for SYSMAC CS Series
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Page 186: ...146 List of Instructions by Function Code Section 2 4 ...
Page 1320: ...1280 Model Conversion Instructions Unit Ver 3 0 or Later Section 3 35 ...
Page 1390: ...1350 CJ series Instruction Execution Times and Number of Steps Section 4 2 ...
Page 1391: ...1351 Appendix A ASCII Code Table ASCII SP Four leftmost bits Four rightmost bits ...
Page 1392: ...1352 ASCII Code Table Appendix A ...
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