| The 'Station Number', 'PC Number' and
'Message wait time' can be set by using the address field in the
IODevices form as follows:
IO Devices form
Protocol: MELSEC or MELSEC1
Address: stationno[,pcno[,waittime]]
where:
[ ] indicates an optional setting.
stationno = Station Number
The station number is used in a RS422/RS485 multidrop configuration
to identify each station. On the Computer Link Module (AJ71) this
station number is set by two rotary switches. In a point to point
connection (PC-PLC) the station number is commonly set to 00, but
every other setting is possible, as long as the number set by the
rotary switches is equal to the number set in Citect. The Station
Number specified in the Citect forms is represented in decimal, and
the valid range is 00 to 31. This setting is NOT optional.
pcno = PC CPU number
The PC CPU number is used to access a specific PLC CPU in the
MELSEC NET. So, if the Computer Link Module is placed in the master
of the MELSEC NET, then every local station in the MELSEC NET can
be reached by setting the corresponding PC CPU number. If
communication is needed with the PLC CPU where the Computer Link
Module is placed, the number 255 (indicating host or 'self') has to
be set. This PC CPU number specified in the Citect forms is
represented in decimal, and the valid range is 00 to 64 and 255.
This setting is optional, and the default is 255.
waittime = Message wait time
This is a time delay required for some computers to switch from
send to receive states. The message wait time determines the
minimum waiting time before the Computer Link Module sends data
after receiving it from the computer. This is useful when simple
RS232/RS485 converters are used. This Message Wait Time specified
in the Citect forms is represented in decimal, and the valid range
is 0 to 15 (representing a delay of 0 to 150msec). This setting is
optional, and the default is 0.
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