Bay Technical Associates 529H User Manual
Page 14
IMPORTANT: Before you proceed with cabling, you must know
whether the devices you are connecting to your multiport are DTE
(Data Terminal Equipment) or DCE (Data Communication
Equipment). The following devices are generally DTE: terminals,
printers, and computers like the IBM PC. The following devices are
DCE: modems and some computers.
If your device transmits data on Pin 2 or receives data on Pin 3, it is
DTE. If your device receives data on Pin 2 and transmits data on Pin
3, it is DCE. However, to verify the interface requirements for your
device, please refer to the Owner's Manual for that device.
BayTech's standard configuration of its multiports is all ports DCE with
DB-25 female connectors. DCE ports use the following signals for
communication:
DCE PORT SIGNALS
Pin
EIA-232
Signal
Direction
Description
1
PGND
----
Protective ground
2
TX
Input
Data in
3
RX
Output
Data out
4
RTS
Input
Internally enabled if no wire connected
(normally not used).
5
CTS
Output
-12V when multiport's buffer is full.
6
DSR
Output
+12V when multiport powers-up.
7
SGND
----
Signal ground
8
DCD
Output
+12V when multiport powers-up.
20
DTR
Input
Transmit enabled when +12 V.