Delta AH500 Programming Manual page 563

Additional remark:
1. If the value in m or n exceeds the range, the operation error occurs, the instruction is not
executed, SM0 is ON, and the error code in SR0 is 16#200B.
2. The flags related to the instruction RS/MODRW:
Flag
COM1 COM2
The data is sent through COM1/COM2. If users want to use the
instruction RS/MODRW to send and receive the data, they have to
use the pulse instruction to set SM96/SM97 to ON. When the
SM96 SM97
instruction is executed, the PLC sends and receives the data. After
the sending of the data is complete, the system automatically resets
SM96/SM97 to OFF.
SM98 SM99 When SM98/SM99 is ON, the PLC is waiting to receive the data.
Reception through COM1/COM2 is complete. After the receiving of
the data is complete, the system automatically sets SM100/SM101
to ON. When SM100 is ON, the data received can be processed.
SM100 SM101
After the processing of the data received is complete, users have to
reset SM100/SM101 to OFF.
An error occurs during the reception of the data by using the
instruction MODRW or the instruction RS. The error codes are
SM102 SM103
recorded in the error logs.
If users set the communication timeout (in SR210/ SR211, SR213/
SR214) and no data is received after the timeout period, the flag is
SM104 SM105
ON. After the problem is solved, users have to reset SM104/SM105
to OFF.
The choice between the 8-bit processing mode and the 16-bit
processing mode
SM106 SM107
ON: The 8-bit processing mode
OFF: The 16-bit processing mode
Data reception complete flag
The receiving of data through COM1 is complete.
ON: when the PLC receives data, it will determine whether there is
any interrupt characters (SR621/SR622 low byte). If there is, it will
run the interrupt task and then stop receiving data even if there is
data that have not been received.
SM108 SM109
OFF: when the PLC receives data, it will determine whether there is
any interrupt characters (SR621/SR622 low byte). If there is, it will
run the interrupt task and after that it will continue receiving
data till the reception is complete. The receiving data length is n
(default).
C ha pt er 6 A p pl i e d In s tr uc t io n
Description Action
Users 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
users reset it
to OFF.
The system
automatically
sets the flag
to ON, and
users reset it
to OFF.
The system
automatically
sets the flag
to ON, and
users reset it
to OFF.
Users set the
flag to ON
and reset it
to OFF.
Users set
the flag to
ON and
reset it to
OFF.
6 - 3 9 5