Omron WS02-9094G - V1.0 Operation Manual page 117

Operating the Network
Sync / Unsync commands
Global-Control Sync command
PLC Cycle
PROFIBUS Cycle
Slave Output
Refresh Cycle
Transmitting Global-
Control Commands using
CX-Profibus
1,2,3...
102
Sending a Global-Control - Sync command to a slave device has the following
effect
• The slave device will update its physical outputs only once with the last
received PROFIBUS output data, despite new output data being received
from the PROFIBUS Master Unit.
• If a new Global-Control - Sync command is sent, the slave device will
update its physical outputs only once, with the most recent received out
put data.
• If a Global-Control - Unsync command is sent, the slave device will revert
back to its original situation, and transfer updated output information to
the Master Unit with each subsequent I/O data exchange message.
Note If a Global-Control command contains both a Sync and an Unsync command,
the Unsync will prevail.
The figure shown below illustrates the Sync / Unsync feature as implemented
by the CS1/CJ1W-PRM21 PROFIBUS Master Unit.
Instruction Instruction
Execution Execution
Sync
transmitted transmitted
Sync command causes
immediate refresh of
slave outputs, and
freezes slave output
refresh process.
Note The Global-Control command as set in the CIO words is transferred to the
Unit together with the I/O data, but the Global-Control command is sent over
the PROFIBUS network, following the I/O data. This means that the outputs of
the targeted slave device will be updated with the values sent to the slave
prior to the Global-Control command.
CX-Profibus provides a means to transmit Global-Control commands from the
PC, through the CS1/CJ1W-PRM21 Master DTM Diagnosis User Interface -
Online Operations tab. This means uses the same CIO words as described
above
To accomplish a Global-Control command transmission, per from the follow-
ing sequence.
1. Make sure the CS1/CJ1W-PRM21 Master DTM is online with the PROFI-
BUS Master Unit.
2. Open the CS1/CJ1W-PRM21 Master DTM Diagnosis User Interface.
Global-Control Unsync command
Instruction
Execution
Sync
Sync command causes
immediate refresh of
slave outputs with last
received PROFIBUS
output data.
Section 3-6
Instruction
Execution
Unsync
transmitted
Unsync command
cancels Sync command
and causes immediate
refresh of slave outputs
and with last received
PROFIBUS output data.