Honeywell 620 PLC

When down loading a program for a Honeywell 620 what must be done.

I know it is more then just down loading the program??

I have never used a Honeywell PLC but most PLC's require the processor to be in the proper mode to accept a download. I.E. Program mode. Then when the program is downloaded it must be switched into some kind of run mode so that it will start executing the code.

Sometimes the software will prompt you to enter these modes, some don't. Hopefully this helps.

Wow.... it has been a LONG time since I have heard the HW 620 mentioned..did a lot of programming of it in the late 1980s, when it was part of the Honeywell S9000 system. Powerful unit in its day.
Also known as a Klockner-Moeller IPC620.

Here is all you need to know...
http://downloads.applied-automation.com/sam/honeywell/620/