Refresh Instruction (Com) - Mitsubishi MELSEC Q Series Programming Manual

COM
7.6.9

Refresh instruction (COM)

COM Refer to Section 7.6.10 for the COM instruction of the following CPU modules.
• Basic model QCPU of serial No. 04122 or later
• High Performance model QCPU of serial No. 04012 or later
• Process CPU of serial No. 07032 or later
• Redundant CPU
• Universal model QCPU
• LCPU
COM
Setting
Data
––
Function
(1) Use the COM instruction when:
(a) It is desired to increase the speed of transmission/reception processing to/from the
remote I/O stations.
(b) It is desired to ensure reliable data transmission/reception with other stations that use
different scan times during the execution of the data link.
(2) The processing of the COM instruction differs depending on whether the special relay
SM775 is ON or OFF.
• When SM775 is OFF: Performs auto refresh and communication with a peripheral
device *
• When SM775 is ON: Performs communication with peripheral device only *
*1: The following processing is performed in communication with peripheral device:
*2: The auto refresh includes the following processing:
7-134
Internal Devices
R, ZR
Bit Word
2
1 *
• Monitor processing of other stations
• Read processing by the serial communications module of the buffer memory of another intelligent
function module
• Refresh of MELSECNET/10H
• CC-Link refresh
• Auto refresh of intelligent function modules.
High
Basic
performance
J \
U \G
Bit Word
––
Process
Redundant Universal LCPU
COM
Zn Constants Other
1