28
RS-232
↔
485/422 CONVERTERS
Appendix A. Pinning
Table 3. RS-232 interface
(* denotes pins that are used).
Pin Circuit
Description
Signal
Type
Direction
when configured as
DCE
DTE
1*
AA
Protective Ground
Ground
-
2*
BA
Transmitted Data
Data
Input
Output
3*
BB
Receive Data
Data
Output
Input
4*
CA
Request to Send
Control
Input
Output
5*
CB
Clear to Send
Control
Output
Not connected
6*
CC
Data Set Ready
Control
Output
Not connected
(held
high)
7*
AB
Signal Ground
Ground
-
8*
CF
Data Carrier Detect
Control
Output
Input
NOTE
Pins 9 through 25 are not used.
