System information

17-Nov-2014 G2T Programmers Guide Rev-A
71
8.1.2. Serial
The C3-001 offers a standard DB-9 serial port with multi-serial
interfaces (RS-232C, RS-422A, and multi-drop RS-485). Additionally,
the CPU has a USB 2.0 (Type-A) interface that may be used for
remote control.
8.1.2.1. DB-9 Connector
8.1.2.1.1. Changing the Serial Mode
The C3-001 CPU is delivered in the default state using the RS-232C
control protocol. RS-485 and RS-422A are also available. The serial
mode cannot be changed through the front panel. To change
the serial control mode, use the GET?/SET value 86 over one of the
remote interfaces. See Section 5.2.3 for more details. The current
serial mode is identified by the MODE LED on the CPU. See Section
8.4 for identification.
8.1.2.1.2. Setting the RS-485 Address
When in the RS-485 control mode, the unit needs to have an
address. The factory default address is 0. The Network ID is used as
the RS-485 address. Refer to Section 5.2.3 for more details.
When addressing a system over RS-485, all commands must be
preceded by the systems RS-485 address.
8.1.2.1.3. Serial Port Pin Assignment
The DB-9 serial port has the following pin assignment:
Pin
Number
RS-232C
Mode
RS-422A
Mode
RS-485
Mode
1
Not Used
Transmit Data – (out)
Not Used
2
Transmit Data (out)
Transmit Data + (out)
Not Used
3
Receive Data (in)
Receive Data + (in)
Data +
4
Not Used
Receive Data – (in)
Data -
5
Ground
Ground
Ground
6
Not Used
Clear To Send -
Not Used
7
Clear To Send
Clear To Send +
Not Used
8
Ready To Send
Ready To Send +
Not Used
9
Not Used
Ready To Send -
Not Used