A customer asked me to provide a DB9 serial connection plug on both ends of a cat5 cable run(this is also a shielded cat5 cable,which is used throughout the plant).One end will be male ,and one end female DB9 to CPE.I have very little knowledge on this subject,however I do have the termination kit,and the connectors already.Any advice,links,play by play,would be great.Or,is this even possible with a Cat5 cable?Thanks.
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DB9 Serial connector termination 1
- Thread starter rpearson
- Start date
- Thread starter
- #3
Check out this site and click on cable you are trying to make for pinout.
You just wire it straight through, but you only really need to worry about pins 2,3(transmit) and 4.5(recieve). On a DB9 pins 2,3,4,5 and on DB25 2,3,7,20.
Good luck!!
You just wire it straight through, but you only really need to worry about pins 2,3(transmit) and 4.5(recieve). On a DB9 pins 2,3,4,5 and on DB25 2,3,7,20.
Good luck!!
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1
- #5
daronwilson
Vendor
RS-232 is likely the most mis-implemented standard. In short, it could take as few as three wires to do bidirectional communication. This connection implements no hardware handshaking. Pins 2 and 3 are the two data pins, and likely you need to make this cable straight through, so on your DB-9 you need to connect pin 2 on one end to pin 2 on the other, same with pin 3. I would put the drain wire off the shield on pin 5 which is the ground. That way you get the shielding effect of a ground over the cable pairs.
Now, which wires to use. I have heard some people say you should put the data wires on a twisted pair, and then I've heard others say to use one pair (two wires) for tx, and another pair (two wires) for the rx. According to Serial Port Complete by Jan Axelson, when using shielded twisted pair wire for RS-232 you should couple each signal wire with a ground. So if you want to try that, you would use something like white/blue for pin 2, and blue/white to ground. White/orange to pin 3, orange white to ground.
Now, depending on who implemented the standard, you may need only those three wires or you may need to connect more to enable hardware flow control. There are two ways to do this:
Full Handshake: In this mode, you connect the Request to Send on one end to the Clear to Send on the other. For a DB9 that would be pin 7 at one end to 8 at the other, and pin 8 to pin 7 (crisscross). In addition, you would take the Data Set Ready on one end, connect it to the Carrier Detect on the same end, and hook those up to the Data Terminal Ready on the other end. Obviously do this for both ends. SO, pins 1 and 6 at one end, to pin 4 at the other end. And of course pin 4 to pins 1 and 6 on the other end. In this mode, the device on each end must hold the various control lines in the proper state to get the other device to transmit and receive properly. This only works if all the hardware handshaking is fully implemented on each end.
Loopback Handshake: In this mode, we 'fool' each device into thinking that it has permission to transmit at any time. This can be very helpfull, but if the device sends too much data and is expecting to be told to 'wait' by the other end, it won't be able to do that and data will be lost. To build this cable, you take the basic three wire cable and loop back the following pins at EACH end (you only have three wires going between the two plugs). Pin 7 to pin 8 (CTS to RTS), Pins 1, 4, and 6 tied together (DSR, DTR, CD).
Ahh serial, so much to deal with for it, hopefully your basic three wire setup will work and you won't have to bother with the extra wiring
Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
Now, which wires to use. I have heard some people say you should put the data wires on a twisted pair, and then I've heard others say to use one pair (two wires) for tx, and another pair (two wires) for the rx. According to Serial Port Complete by Jan Axelson, when using shielded twisted pair wire for RS-232 you should couple each signal wire with a ground. So if you want to try that, you would use something like white/blue for pin 2, and blue/white to ground. White/orange to pin 3, orange white to ground.
Now, depending on who implemented the standard, you may need only those three wires or you may need to connect more to enable hardware flow control. There are two ways to do this:
Full Handshake: In this mode, you connect the Request to Send on one end to the Clear to Send on the other. For a DB9 that would be pin 7 at one end to 8 at the other, and pin 8 to pin 7 (crisscross). In addition, you would take the Data Set Ready on one end, connect it to the Carrier Detect on the same end, and hook those up to the Data Terminal Ready on the other end. Obviously do this for both ends. SO, pins 1 and 6 at one end, to pin 4 at the other end. And of course pin 4 to pins 1 and 6 on the other end. In this mode, the device on each end must hold the various control lines in the proper state to get the other device to transmit and receive properly. This only works if all the hardware handshaking is fully implemented on each end.
Loopback Handshake: In this mode, we 'fool' each device into thinking that it has permission to transmit at any time. This can be very helpfull, but if the device sends too much data and is expecting to be told to 'wait' by the other end, it won't be able to do that and data will be lost. To build this cable, you take the basic three wire cable and loop back the following pins at EACH end (you only have three wires going between the two plugs). Pin 7 to pin 8 (CTS to RTS), Pins 1, 4, and 6 tied together (DSR, DTR, CD).
Ahh serial, so much to deal with for it, hopefully your basic three wire setup will work and you won't have to bother with the extra wiring
Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
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