T1K–MODBUS
Specifications
Installation and
Safety Guidelines
2–6
T1K–MODBUS Specifications
The Hold Outputs DIP Switch 5 determines the slave outputs’ response to a
communications failure. If DIP switch 5 is in the ON position, the outputs in that slave
unit will hold their last state when a communication error occurs. If OFF, the outputs
in that slave unit will turn off in response to a communications error.
SW 5 Hold Outputs
OFF
Turn OFF
ON
Hold Last State
WARNING: Selecting “HOLD LAST STATE” means that outputs in that slave
will not be under program control in the event of a communications failure.
Consider the consequences to process operation carefully before selecting
this mode.
DIP Switch 6 selects the baud rate for the RJ12 serial port. All other serial port
communication parameters are fixed. The port defaults are listed in the
specifications tables in the beginning of this chapter.
SW 6 RJ12 Serial Port
Baud Rate
OFF
9600 bps
ON
19200 bps
DIP Switch 7 selects the T1K–MODBUS addressing mode. Select the OFF
position if the T1K–MODBUS is to be used with a MODBUS master that operates in
the 584/984 addressing mode. Select the ON position if the T1K–MODBUS is to be
used with a DirectLogic PLC CPU operating as the MODBUS master. The modes
are discussed in Chapter 3.
SW 7 MODBUS RTU
Addressing Mode
OFF
584/984 MODBUS Slave
ON
DirectLogic PLC MODBUS Slave
DIP Switch 8 either enables or disables the CTS pin on the RJ12 serial port. Place
the switch in the ON position if the connected serial device requires RTS/CTS
control. Otherwise place the switch in the OFF position if only 3–wire
communication (TX, RX, GND) is required.
SW 8 CTS for RJ12 Serial Port
OFF
Disable
ON
Enable
