Panasonic FP E Series User Manual page 215

Setting of unit numbers
By default, the unit number for the communication port is set to 1 in the system registers.
In a PC(PLC) link that connects multiple PLCs on the same transmission line, the unit number must be
set in order to identify the different PLCs.
The unit number is specified either by using the unit number setting switch, SYS1 instruction or the
system register.
Note1) The priority order for station number settings is as follows:
1. Unit number settings switch
2. SYS1 instruction
3. System registers
Note2) Station numbers should be set sequentially and consecutively, starting from 1, with no breaks
between them. If there is a missing station number, the transmission time will be longer.
Note3) If fewer than 16 units are linked, the transmission time can be shortened by setting the largest
station number in system register no. 47.
Unit numbers are the numbers to identify the different PLCs on the same network. The same number
must not be used for more than one PLC on the same network.
If unit number setting switch is 0, SYS1 instruction and the system register Is valid.
If unit number setting switch is a number other than 0, the unit number setting switch is valid, and the
unit number setting with the system register is ignored. The same unit number is given to both COM1
port and COM2 port.
Note:
When using the PC(PLC) link with the RS232C, the number of units is 2.
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