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Knowledge Base > Discontinued Products > 8×8 DSP

What is the RS-232 pinout on my Symetrix manufactured product?

All Symetrix manufactured products with RS-232 ports have them wired straight-through. Only pins 2, 3 and 5 are required. If you want to make your own cable, refer to the RS-232 standard below:

RS-232 Standard Configuration: The following table documents the pin assignments for the RS-232 standard using DB9 and DB25 connectors. Following the table is a set of diagrams to assist in identifying what pin numbers are assigned to each pin inside the different connectors.

The RS-232 standard:

DB-25 DCE DB-9      
1     AA x Protective Ground
2 TXD 3 BA I Transmitted Data
3 RXD 2 BB O Received Data
4 RTS 7 CA I Request To Send
5 CTS 8 CB O Clear To Send
6 DSR 6 CC O Data Set Ready
7 GND 5 AB x Signal Ground
8 CD 1 CF O Received Line Signal Detector
9     x Reserved for data set testing
10     x Reserved for data set testing
11       x Unassigned
12 SCF     O Secondary Received Line Signal Detector
13 SCB     O Secondary Clear to Send
14 SBA     I Secondary Transmitted Data
15 DB     O Transmission Signal Element Timing
16 SBB     O Secondary Received Data
17 DD     O Receiver Signal Element Timing
18       x Unassigned
19 SCA     I Secondary Request to Send
20 DTR 4 CD I Data Terminal Ready
21 CG     O Signal Quality Detector
22   9 CE O Ring Indicator
23 CH/CI     I/O Data Signal Rate Selector
24 DA     I Transmit Signal Element Timing
25       x Unassigned

Where is Pin 1?

25 pin DB25 Male Connector: Image

25 pin DB25 Female Connector: Image

9 pin DB89 Male Connector: Image

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