Wiring The Serial Port - GE AquaTrans AT868 User Manual

Wiring the Serial Port

Wiring an RS232 Interface
Table 1-1: RS232 Connection to DCE or DTE Device
Infrastructure
COMMUNICATION
TB
5
4
3
2
1
*For standard GE Infrastructure Sensing cables 704-659, -660, -661 and -662.
Installation
The Model AT868 flow transmitter is equipped with a built-in serial
communications port. The standard port is an RS232 interface, but an
optional RS485 interface is available upon request. Proceed to the
appropriate sub-section for wiring instructions. For more information
on serial communications refer to the EIA-RS Serial Communications
Manual (916-054).
Use the serial port to connect the Model AT868 flow transmitter to a
printer, an ANSI terminal or a personal computer. The RS232
interface is wired as Data Terminal Equipment (DTE), and the signals
available at the COMMUNICATION terminal block are shown in
Table 1-1 below.
1. Follow the instructions on page 1-4 to prepare the unit before you
connect power.
2. Use the information in Table 1-1 below to construct a suitable
cable for connecting the Model AT868 to the external device. If
desired, an appropriate cable may be purchased from the factory.
Colors for GE
Sensing Cable
Description
(flying leads)*
DTR (Data
White
Terminal Ready)
Yellow
(Clear to Send)
Green COM (Ground)
Red RX (Receive)
Black TX (Transmit)
Note: Signal names that imply direction (e.g., transmit and receive)
are named from the point of view of the DTE device (the GE
Infrastructure Sensing meter is usually considered the DTE
device). When the RS232 standard is strictly followed, these
signals are labeled with the same name and pin # on the DCE
device side as well. Unfortunately, the convention is not
followed because the DTE and DCE side get confused.
Therefore, connections that imply direction are changed to
reflect their direction on the DCE side.
DCE
Signal DB25
Pin #
20
CTS
4
7
2
3
September 2004
DCE DTE DTE
DB9 DB25 DB9
Pin # Pin # Pin #
4 20 4
7 5 8
5 7 5
3 3 2
2 2 3
1-9