Micrologix 1400 RTU rs485 CH0

[Marcosbelgo]

Hi friends,

I know that this question already was talked but, in my search, this dont be clear. I have to connect Micrologix 1400 to RS485 modbus rtu network.

1 - I know that the 1763-NC01 is the most safe option, but I dont have and wont buy it now.
2 - Can I construct my own cable just pin-out, without resistors? Wich is the reasons that it can damage the equips?
3 - The cable has 15 cm max, and I can use low baud rate......
4 - If is extremaly nescessary to use a terminator resistors, what is its impedance and is just solder between a-b terminals?
5 - About this document posted here:
1763-NC01 Cable Connections:
http://www.plctalk.com/qanda/attachm...4&d=1367597269

the image is confuse. For I understand: the pin 8A of conector drawed at the document, is the top or bottom 6-7-8 pin looking in front of PLC mini din port?

Thanks very much.

[OkiePC]

Originally Posted by Marcosbelgo

Hi friends,

I know that this question already was talked but, in my search, this dont be clear. I have to connect Micrologix 1400 to RS485 modbus rtu network.

1 - I know that the 1763-NC01 is the most safe option, but I dont have and wont buy it now.

It's the easiest, and depending on your pay rate, most cost effective.

2 - Can I construct my own cable just pin-out, without resistors? Wich is the reasons that it can damage the equips?

Yes, you can do that. There is very little chance of damaging equipment that I am aware of. Just be careful to wire it right the first time. You might get away without using termination resistors, but I would not recommend putting a system into service without proper termination.

3 - The cable has 15 cm max, and I can use low baud rate......
4 - If is extremaly nescessary to use a terminator resistors, what is its impedance and is just solder between a-b terminals?

120ohm.

5 - About this document posted here:
1763-NC01 Cable Connections:
http://www.plctalk.com/qanda/attachm...4&d=1367597269

the image is confuse. For I understand: the pin 8A of conector drawed at the document, is the top or bottom 6-7-8 pin looking in front of PLC mini din port?

Thanks very much.

The pin numbers on the left are for the connector on the left, likewise, the pin numbers on the right are for the connector on the right in the drawing.

[Marcosbelgo]

Thanks OkiePC,
how do I make this welding? Just one 120 ohm resistor between a-b terminals? Should I do welding this at the tip of my conector? This can be exposed? The resistor is a normally resistor? Or a especial resistor???
Thanks