Descriptions On The Communication-Related Flags And Registers - Delta AS Series Programming Manual

6.19.3 Descriptions of the Communication-related Flags and
Registers
Communication-related flags (SM)
Flag
COM1 COM2 Card 1
SM96 SM97 SM76
SM98 SM99 SM78
SM100 SM101 SM80
SM102 SM103 SM82
SM104 SM105 SM84
SM106 SM107 SM86
Card 2
Data sending request flag
If you want to use the instruction to send and
receive data, you must use the pulse instruction to
SM77
set the flag to ON. When the instruction is
executed, the PLC sends and receives the data.
After sending the data, the system automatically
resets the flag to OFF.
When the flag is ON, the PLC is waiting to receive
SM79
the data.
Reception complete flag
After receiving the data, the system automatically
SM81
sets the flag to ON. When the flag is ON, the data
received can be processed. After processing the
data received, you must to reset flags to OFF.
Data receiving error flag
SM83
An error occurs during receiving data using the
data receiving instruction.
Communication timeout error flag
If you set the communication timeout (in SR) and
SM85
no data is received after the timeout period, the flag
is ON. After the problem is solved, you must reset
the flag to OFF.
The choice between the 8-bit processing mode and
the 16-bit processing mode
SM87
ON: 8-bit processing mode
OFF: 16-bit processing mode
Cha p ter 6 App l ied Ins truc tio ns
Description Action
You set the flag to ON, and
the system automatically
resets it to OFF.
The system automatically
sets the flag to ON and
resets it to OFF.
The system automatically
sets the flag to ON, and
you reset it to OFF.
The system automatically
sets the flag to ON, and
you reset it to OFF.
The system automatically
sets the flag to ON, and
you reset it to OFF.
You set the flag to ON and
reset it to OFF.
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