Teledyne 6200E - Sulfides Analyzer - Manual (Page 106)

Operating Instructions Model 6200E Instruction Manual
106 M6200E Rev: A1
When COM2 is configured for RS-485 operation the port uses the same female DB-9 connector on
the back of the instrument as when Com2 is configured for RS-232 operation, however, the pin
assignments are different.
Female DB-9 (COM2)
(As seen from outside analyzer)
(RS-485)
1 2 3 4 5
6 7 8 9
GND RX/TX +
RX/TX -
Figure 6-10: Back Panel connector Pin-Outs for COM2 in RS-485 mode.
The signal from this connector is routed from the motherboard via a wiring harness to a 6-pin
connectors on the CPU card, CN5.
CN5
(Located on CPU card)
(As seen from inside analyzer)
2 4 6
1 3 5
RX/TX +
RX/TX -
GND
Figure 6-11: CPU connector Pin-Outs for COM2 in RS-485 mode.
6.10.5. DTE and DCE Communication
RS-232 was developed for allowing communications between data terminal equipment (DTE) and
data communication equipment (DCE). Basic terminals always fall into the DTE category whereas
modems are always considered DCE devices. The difference between the two is the pin assignment
of the Data Receive and Data Transmit functions.
• DTE devices receive data on pin 2 and transmit data on pin 3.
• DCE devices receive data on pin 3 and transmit data on pin 2.