IAI America RCM-GW-DV - Manual (Page 105)

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DeviceNet Gateway
7.4 Command Transmission
Commands can be used in the command specification mode.
A timing chart of command transmission is given below.
Every time control/status data is exchanged for any of the connected axes in normal operations, the
Gateway Unit analyzes each request command and responds to the command.
The PLC and Gateway perform the following steps:
[1] After confirming zeros in a response command, the PLC application sets the next request command
and data required.
[2] After detecting non-zero data in the request command, the Gateway Unit sends the request data to
the applicable axis.
[3] After receiving a response from the applicable axis, the Gateway outputs a response result.
[4] After checking the response result, the PLC application clears the request command.
[5] After detecting that the request command has been cleared, the Gateway clears the response
command and waits for the next command.
Steps [1] through [5] are repeated in continuous command transmissions.
[1]
[2]
[3]
[4]
[5]
Output of PLC request
(PLC
→ GW)
Request command,
data
Request = 0000H
Transmission to/from the
controller is performed by
the Gateway
Gateway response
Response = 0000H
Response command,
data