Length of cable - PCIe 8430/16

[navinTerabee]

Hello, 

I wanted to know the maximum length of the cables that can be used with PCIe 8430/16(RS232) card at 115200bps. It is not specified in the datasheet. 

[JÞB]

---

@navinTerabee wrote:

Hello, 

I wanted to know the maximum length of the cables that can be used with PCIe 8430/16(RS232) card at 115200bps. It is not specified in the datasheet. 

---

See this white paper

With proper shielding and a low noise environment you can typically get out around 50 ft.   That is not often the case though! not all cables a shielded the same and not all places you want to be are low noise.

[cstorey]

RS232 max cable length is dependent on cable capacitance and the voltage that you operate at.  Generally at 9600bps its about 10-25m with good cables when using 12-15V, and as bit rate increase length drops fast.  So its all dependent on the cable you choose and the voltage your talker listeners support.  RS232 isn't a good "long haul" data transfer protocol. Use RS422/485 for long hauls.

Actually, the NI data sheet has a spec here on pg 17 (2500pF equivalent) - http://www.ni.com/pdf/manuals/371332g.pdf

This reference confirms my earlier comment - https://www.tldp.org/HOWTO/Remote-Serial-Console-HOWTO/serial-distance.html

[Minions]

RS-232 has an expected impedance of 100-ohms.  Try using a low capacitance (<17pf/lf) matched impedance (100-ohm) wire.  Most CAT-5 cable meets these criteria without the individual shielding.