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RS232 Pin Connection Reference


Figure 1. DB9F to DB25M, Null Modem (Crossover)

diagram


Figure 2. DB25F to DB25M, Null Modem (Crossover)

diagram


Figure 3. DB9F to DB25M, Straight

diagram


Figure 4. RS232C PC 9-Pin

Pin (DB9) Signal Function Label I/O Type
1 Carrier Detect CD Input
2 Receive Data RD Input
3 Transmit Data TD Output
4 Data Terminal Ready DTR Output
5 Signal Ground SG ---
6 Data Set Ready DSR Input
7 Request to Send RTS Output
8 Clear to Send CTS Input

Figure 5. RS232C PC 25-Pin

Pin (DB25) Signal Function Label I/O Type
1 Protective Ground PG ---
2 Transmit Data TD Output
3 Receive Data RD Input
4 Request to Send RTS Output
5 Clear to Send CTS Input
6 Data Set Ready DSR Input
7 Signal Ground SG ---
8 Carrier Detect CD Input
20 Data Terminal Ready DTR Output

Figure 6. DB25M/RJ45 Modular Adapter (This pinout requires separate null modem adapter, call 805.419.0226 for part number.)
EIA/TIA 561

DB25 Wire Color RJ45
1 No Connection ---
2 Green 5
3 Yellow 6
4 White 8
5 Brown 7
6 Blue 1
7 Red 4
8 Orange 2
20 Black 3

Figure 7. DB9F/RJ45 Modular Adapter
EIA/TIA 56

DB9 Wire Color RJ45
1 Orange 2
2 Yellow 6
3 Green 5
4 Black 3
5 Red 4
6 Blue 1
7 White 8
8 Brown 7
9 --- ---

Sihler Engineering / dncsoftware.com
234 Lightwood Street
Camarillo California 93012
Phone / Text: (805) 419-0226
Email: support@dncsoftware.com

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