About Sysmac Net Link/Sysmac Link Operations - Omron SYSMAC CV Series Operation Manual

Network Instructions

5-36-7 About SYSMAC NET Link/SYSMAC LINK Operations

Timing
Enabled
Flag
Execution
Error Flag
Data Processing for
Network Instructions
Programming Example:
Multiple Instructions
SEND(192), RECV(193), and CMND(194) are based on command/response
processing. That is, the transmission is not complete until the sending node re-
ceives and acknowledges a response from the destination node, unless the re-
sponse function is disabled in the control word or data is being broadcast to all
nodes in a network. Refer to the SYSMAC NET Link System Manual or SYS-
MAC LINK System Manual for details about command/response operations.
If more than one network instruction (SEND(192)/RECV(193)/CMND(194)) is
used through one port, the following flags must be used to ensure that any pre-
vious operation has completed before attempting further network instructions.
Flag
Port #0 to #7
Enabled Flags
(A50200 to A50207)
Port #0 to #7
Execution Error Flags
(A50208 to A50215)
Port #0 to #7
Completion Codes
(A503 to A510)
Instruction Transmission
received completes
normally
Data is transmitted on a network when SEND(192), RECV(193), or CMND(194)
is executed. Final processing for transmissions/receptions is performed during
servicing of Link Units.
Instruction execution and peripheral device servicing are processed in parallel,
thus data from network instructions might not be processed synchronously. To
synchronize data processing, set the PC to synchronous execution or use the
IOSP(187) and IORS(188) instructions.
To ensure successful SEND(192)/RECV(193) operations with more than one in-
struction for a single port, your program must use the Enabled Flag and Error
Flag to confirm that execution is possible. The following program shows one ex-
ample of how to do this for port 4 in a SYSMAC NET Link System. The program is
effective when both bit 000000 and the Port 4 Enable Flag (A50204) are ON.
Functions
Enabled Flags A50200 to A50207 are OFF during
network instruction execution for ports #0 to #7,
respectively. Do not start a network instruction for a port
unless the corresponding Enabled Flag is ON.
OFF following normal completion of a network
instruction (i.e., after reception of response signal)
ON after an unsuccessful network instruction attempt.
Error status is maintained until the next network
instruction.
Error types:
Time-out error (command/response time greater than
the response monitoring time set in the control words)
Transmission data errors
A503 to A510 contain the completion codes for errors
that occur during network instruction execution for ports
#0 to #7, respectively. The code for normal completion of
a network instruction is 0000. Refer to the SYSMAC
NET Link System Manual or SYSMAC LINK System
Manual for details about error codes.
Instruction Transmission
received error
Section 5-36
Instruction
received
423