User guide

Communication Capabiliites
890 USE 108 00 August 2001 71
MODBUS Port
Parameters
(2-Position Slide
Switch)
Use the communication parameter slide switch on the front panel of the controller to
specify Modbus port parameters as follows.
In the default position ( = ), port one automatically adopts these parameters:
9600 baud, EVEN parity, RTU mode.
In the mem position ( O ) the port assumes the parameters that you have
specified in the configurator editor in panel software.
Use of this switch in the context of Modbus Plus communications is discussed in
Modbus Plus Communications E984-265/275/285, p. 84
The first time that you connect a programming panel to start the controller, your
panel device must use the following Modbus port parameters: 9600 baud, EVEN
parity, RTU mode, 1 stop bit, Modbus port address 1.
The following figure shows the Modbus port switch.
Note: Port 2 of the A984-1xx, and E984-24x/251/255 models does not support the
following Modbus port parameters.
ASCII 7 data bits - 1 stop - no parity= 9 bits (illegal)
RTU 8 data bits - 2 stop - parity = 12 bits (illegal)
default
mem
9600 Baud, EVEN Parity, RTU Mode
(1 Stop Bit, 8 Data Bits)
Modbus Port Address 1
Port 1 - 50, 75, 110, 150, 300, 600, 1200,
2400, 4800, 9600, or 19200 Baud
EVEN/ODD/NO Parity (1/2 Stop Bits)
RTU (8 Data Bits) or ASCII (7 Data Bits) Mode
Port 2 - 300, 600, 1200, 2400, 4800, 9600,
or 19200 Baud
EVEN/ODD/NO Parity (1/2 Stop Bits)
RTU (8 Data Bits) or ASCII (7 Data Bits) Mode