K1TTT Technical Reference

Pinouts - Serial (RS232/RS422A)


RS-232C - 25 Pin Connector

Pin Number     Signal Description
----------     ------------------------------
1              Frame Ground (GND)
2              Transmit Data (TD)
3              Receive Data (RD)
4              Request To Send (RTS)
5              Clear To Send (CTS)
6              Data Set Ready (DSR)
7              Signal Ground (GND)
8              Carrier Detect (CD)
9              + Transmit Current Loop Return
11             - Transmit Current Loop Data
18             + Receive Current Loop Data
20             Data Terminal Ready (DTR)
22             Ring Indicator (RI)
25             - Receive Current Loop Return



RS-232C - 9 Pin Connector

Pin Number     Signal Description
----------     ------------------------------
1              Carrier Detect (CD)
2              Receive Data (RD)
3              Transmit Data (TD)
4              Data Terminal Ready (DTR)
5              Signal Ground (GND)
6              Data Set Ready (DSR)
7              Request To Send (RTS)
8              Clear To Send (CTS)
9              Ring Indicator (RI)


RS-422A - 25 Pin Connector

Pin Number     Signal Description
----------     ------------------------------
1              Frame Ground (GND)
3              Receive Data (RD)
7              Signal Ground (GND)
9              Send Data (SD) Invert
10             Send Data (SD) Non-Invert
18             Receive Data (RD) Non-Invert
25             +5V DC


9 Pin To 25 Pin RS232C Conversion

9 Pin Number 25 Pin Number    Signal Description
------------ -------------    -------------------------
1            8                Carrier Detect (CD)
2            3                Receive Data (RD)
3            2                Transmit Data (TD)
4            20               Data Terminal Ready (DTR)
5            7                Signal Ground (GND)
6            6                Data Set Ready (DSR)
7            4                Request To Send (RTS)
8            5                Clear To Send (CTS)
9            22               Ring Indicator (RI)


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