Koyo Port Locking Up - Help!

[Chuck Hoyt]

Hello all,
Everyone was so helpful with my data encryption question several months ago, but now for a new question:
An integrator that I am working with has a pair of Koyo Direct Logic 405 PLCs. He is connected via Com Port 1 on the CPU to a serial radio. The problem is that the port keeps locking up after about 3 to 5 TX & RX. He has replaced the radios from Genas?(sp) to MDS Transnets with no change. The radios have been configured for 9600 baud and 8 data bits, Odd parity and stop bit 1. As I have stated before, I'm a radio guy so I may not know some of the additional details you guys may need to help me out, but I can find out! Thanks again for your help with my last question!
Chuck

 

[icky812]

Do the PLC's have the latest firmware? How about surge supression on the lines between the PLC and radio modem? Sometimes keying up the radio will induce voltage spikes on the coms line.

 

[Tark]

Check to make sure you have the RTS On and RTS Off delays set correctly in the PLCs. When you transmit through a radio, it takes a certain amount of time for the radios to sync up.

Here is a link for setting the RTS On and Off delays -
http://support.automationdirect.com/docs/comportsetup/

I have been using an RTS On delay of 50mS and RTS Off delay of 20mS.

 

[Chuck Hoyt]

Thanks Icky, I'll pass this on.
Chuck

 

[Chuck Hoyt]

Turk,
Very good to know, I have e-mailed him the link.
Thanks for your help last time too!
Chuck

 

[Chuck Hoyt]

Hey everybody,
Thanks for your responses, he figured it out. He was using DirectNet and apparently it is similair to Modbus as far as it needs to have "Buffering On" in the radio!
Thanks!
Chuck