Omron CS1W-SCU21 Operation Manual page 510

Changing Communications Port Settings
The STUP(237) instruction can be used to change the serial communications mode, communications specifi-
cations, and other settings for each port of the Serial Communications Board/Unit during CPU Unit operation.
Executing the STUP(237) Instruction
Use the STUP(237) instruction to change the communications port settings. For example, the STUP(237)
instruction can be used to switch the protocol to Host Link mode without leaving RUN mode and allow the user
to monitor and program the CPU Unit from the host computer when the specified conditions are met while
send/receive sequences for modem and line connections are being executed in protocol macro mode.
STUP Instruction Specifications
Control Data (C)
Set the following items.
Serial Port Number
Set the serial port number (physical port number) of the Serial Communications Board or Unit to which the
remote node is connected. PORT1: 1 (hex)/PORT2: 2 (hex)
Remote Unit Address
Specify the unit address of the Serial Communications Board/Unit for which the serial port is to be changed.
Serial Communications Board: E1 (hex)
Serial Communications Unit: Unit number + 10 (hex)
Setting: 10 to 1F (hex)
Note The CPU Bus Unit number (0 to F) is set using the rotary switch on the front panel of the Unit.
First Word of Port Settings (S)
Set the address of the first word containing the serial port settings. The data is stored starting from word S in
the say way as the port settings in the 10-word area allocated in the DM Area for each port. For details on the
Setup Area, see 2-3 I/O Memory Allocations or 4-2, 5-2, 6-2, and 7-2 Setup Area Allocations.
S
S+1
S+9
When the STUP(237) instruction is executed, the CPU Unit changes the contents of the relevant DM Area in
the Unit, then automatically turns ON the Port Settings Change Bit (words A620 to A635) in the Auxiliary Area.
A620 + unit number
Port 1 Port Settings Change Bit: Bit 1
Port 2 Port Settings Change Bit: Bit 2
Appendix O
Using STUP(237)
Control data (serial port number, remote unit address)
First words of port settings
Serial port number
15
Serial port system setting
Remote unit address
00
10 words per port
491