Ron_S

I concur. If it won't communicate and the error light is on, it's a dud. They are very old plc's.

You at least have to tell us which software you used And...make the files shareable

I didn't mean your pc cpu. I meant the plc cpu. I just used your terminology. Try a test program with a different plc and see if that will simulate.

What CPU are you using? It's sort of telling you that's where the problem lies.   Have you tried a test program with another type of cpu?

He probably did 5 years ago.

Lol, I meant D0 and D1. Thanks, I might have confused him.

DMOV will move a 32 bit number from C235 into D0 Being 32 bit, it will use D1 and D2. You can use DCMP to check when it reaches 75000  

If you have the right cable - yes

Bottom left corner main screen 'Connection Destination' then - 'connection1'  top left corner Click yellow 'plc module'  tick 'transparent mode'  

There are so many reasons. Post your program here and it will become obvious to the pro's

Get the right cable. You'll need to look it up CAB19 rings a bell. Then use transparent mode in communication settings

Insert/overwrite. Insert is selected. Press the keyboard insert key to change back.

Gx developer will work fine. The cable is called an SC09. If you buy the cable from ebay, make sure it has the 25 pin plug with it

Ok, so you have understood the time and date registers. You now have to choose what time of day you want the actions to happen. You then put a line of 'if = '     ie  You want the sprinklers to operate for the 30 minute period at  10:15 at night hour=k22 and minute=k15 SET M0  M0 run timer T0 K18000 M0 turn on Y0 (sprinkler output) T0 reset M0 Use a different M relay to turn on Y0 with each run sprinkler event Have a go at turning that in to code.              

Change plc type to fx2n