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4-4
Section
SRM1(-V2) Communications Functions
276
Node number:
00
When no-protocol communications are used, TXD(48) is used to send data and
RXD(47) to receive data. The maximum amount of data that can be either sent or
received is 259 bytes, including the start/end code.
•
No Start or End Code:
Data (256 bytes max.)
•
Only a Start Code:
ST
Data (256 bytes max.)
•
Only an End Code:
ED
Data (256 bytes max.)
•
Both an Start and End Code:
ST
Data (256 bytes max.)
ED
•
End Code of CR, LF:
LF
Data (256 bytes max.)
CR
•
Start Code 00-FF/End Code CR,LF:
LF
Data (256 bytes max.)
CR
ST
Note
1. The start and end codes are set in DM 6648 to DM 6649 and DM 6653 to
DM 6654 of the PC Setup.
2. When there are several start and end codes, the first part of each will be ef-
fective.
3. When the end code duplicates the transmission data and the transmission is
stopped part way through, use CR or LF as the end code.
4. The start and end codes are not stored.
When sending data from the SRM1(-V2), check that the Transmission Enable
Flag is ON for executing the TXD(48) instruction. The Transmission Enable Flag
will turn OFF while the data is being transmitted and will turn ON again when
transmission is complete.
After the SRM1(-V2) has received data, the Receive Enable Flag turns ON.
When the RXD instruction is executed, the data received will be written to the
specified words and the Reception Complete Flag will turn OFF.
Flag
Peripheral port
RS-232C port
Transmission Enable Flag
AR 0813
AR 0805
Reception Complete Flag
AR 0814
AR 0806
Note
The timing from data reception starting to completion for the SRM1(-V2) is as
indicated below.
Reception Start:
Without start code:
Normal reception status
With start code:
After start code is received.
Transmission Data
Configuration
Transmission Flags