Expansion module extender cables

[Paul Rylatt]

When using the EX-A2X or EX-RC1 with a Visilogic PLC, it is required to put all 8 expansion modules in a row.  This can require a very wide back plate and is not very feasible for projects with a small cabinet footprint.

Is there any thought to creating extension cables that would allow the expansion modules to be placed in multiple rows on a back plate?

[Joe Tauser]

Unitronics' official position is you can not extend the I/O bus.

We have made an "unofficial" 36" extension cable with shielded flat cable that we sell.  It seems to work.

Send me a message if you're interested in one.

Joe T. 

[Ausman]

On 2/8/2019 at 4:45 PM, Joe Tauser said:

an "unofficial" 36" extension cable with shielded flat cable

I have often pondered that solution, wondered why "it is not recommended" and never actually built and tested for myself because I had thought it was 2 things:

1).  due to power required needing more than a ribbon...perhaps the actual main power lines augmented would help?   and

2).  the overall question of how does the plc work out where I/Os are anyway.  Does anyone know (apart from the creators!) the intricacies of this bit of trickery?

If your cable works, Joe, that is worth knowing.  I have had numerous instances of exactly Paul's problem.

cheers, Aus

[kratmel]

I tried to investigate how the expansion adapter EX-A2X bus was built. Standard CMOS logic push-pull output with 5V power supply used.

So I think that it will work through a longer shielded wire. Especially if the expansion units are placed in a metal cabinet.

Also, I encountered the option of placing expansion blocks on a metal plate similar to the additional door.
The blocks were placed on both side - half stood on the rail in front, and half behind. Long extender is not needed in this case.

I liked the access that provided the folding door in the cabinet. But maybe in small box this method it is not applicable.