modicon 484


Thread Starter

Dave Gross

I have a customer who has a Modicon 484. The power supply went bad and the program got scrambled. They had spare parts to get it running but without a program. I was able to use their P180 programmer to add some rungs and verify the 484 operation. They have a cassette tape backup. But nobody knows cable configuration, bauds, etc. The tape loader they have is a STR-Link. I was unable to get program loaded in. Anybody have any suggestions?

It's been a few months since you posted this, so you may well have solved your own problem. In any case, I stumbled onto a few cable diagrams that may be of some use to you.

We have both a P180 programmer and a P190 programmer and have had some difficulty with these in the past. I have recently managed to download a program from a tape backup in the P190 with a direct cable between the PC com port and the P190 port. The connection I used was a 9 - 25 pin cable.

To make one:
Connect the pins 2-2, 3-3,5-7 then on the 9 pin connector connect pins 7-8, and 6-1-4.
On the 25 pin connector connect pins 4-5, and 6-8-20.
THis simply prevents flow control problems between the PC and the P190.
If connecting a PC to a EIA port just cross over the wires 2-3 3-2.

Further, we have a cable that connects to both a p180 port and a EIA port this connection is 25-25. On one end connect pins 4-5, 6-20,13-23 On other end make same pin connections between the two

I don't think you need to worry about baud rates but generally they seem to be 9600 1 startbit 7databits 1stopbit Evenparity for ascii comms for rtu modes just substitute 8databits into the above.

Hope this helps, I'm still a novice