Redundant PLC5/60 software download

Hi all,

I have a redundant PLC5/60B I think. I need to go upload the software modify and download new one. I cant powerd down the PLC. Can anyone tell me wheather I can use DH+ port to do that or I have to go via serial? There is no ethernet module

Yes, if you have a DH+ adapter for you're computer. PLC5 isn't rally redundancy, it's more of a hot backup. Also you will have to download the changes to the other PLC5 too.

Adapter?? Can't I just use RSLinx and configure proper driver?

Well you need those as well. Data Highway Plus (DH+) is an AB proprietary communications protocal. You need some kind of adapter to get your computer on the DH+ network. How were you thinking of connecting?

I thought I may use DB9 to Mini Din serial cable and connect directly to PLC5 DH+ via proper RSLinx driver. I didn't assume any adapters are required.Anyway thanks for help your advice was useful.

I'm glad you checked; that Mini-DIN8 connector is pinned to the Data Highway Plus 3-pin connector directly below it. It is not RS-232.

This has been the computer connection plug for DH+ for about 20 years. The most common way to connect was the 1784-PCMK card and 1784-PCM6 cable, but those have fallen by the wayside as PCMCIA slots become obsolete.

The modern connection is a USB/DH+ cable called the 1784-U2DHP.

You should also be able to use the DB25 serial port; it's just a lot slower. The standard A-B cable is a 1784-CP10, but the port uses the ordinary Rx/Tx/GND pins for a 25-pin DTE-type port, so you can use a straight serial cable and a null-modem adapter.

let's go back to Post #1 for just a second ...

I need to go upload the software modify and download new one.

Click to expand...

OK ... that's probably going to be possible – once you get your communication gear set up ...

BUT ...

I cant powerd down the PLC.

Click to expand...

now THAT might be a problem ... are you aware that you can NOT "download" a program into a running/executing processor? ...

I've got a hunch that when you said that you can't "power down" the PLC that you actually meant that the processor needs to keep right on running/executing its program (and controlling its outputs) DURING the download operation ... sorry, but if that's what you meant, then it won't be possible ...

specifically, you can NOT "download" a program while the processor keeps running/executing and controlling its outputs ...

on the other hand, you MIGHT be able to modify some rungs while the processor keeps running – but a full program "download" is another issue ...

now then ...

IF (that's a big IF) you actually do have some type of "backup" configuration that you're working with, then you MIGHT be able to pull this off without interrupting the system's operation – but you'd need to do some careful research before you proceed ...

suggestion:

make a detailed inventory of exactly what hardware you're dealing with and post the list ... the forum can probably help you sort this out – but the fact is that you can NOT "download" a program into a running/executing processor ...

How about online modifications? One of the PLC is primary another is secondary. There are also two BCM and two BEM modules in PLC5 racks. What if I connect to secondary first do online mods. Than connect to primary and to the same. That should keep the plant alive for the whole time? Is that correct? I will use RS232 already ordered the cable.

If you're going to do online modifications, you can do it directly on the primary PLC. But if you CAN'T afford any downtime, it might be wise to test the modifiactions on another PLC first. After the online mods are done, you can do a download to the secondary processor. JUST be extra careful that you're downloading to the secondary processor. I believe it will have a DH+ address one higher than the primary one.

most of the information that you're going to need is in the user manual for the 1785-BCM module ...

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1785-um524_-en-p.pdf

take a quick look at page 5-21 [Adobe page 85] to get the answers to your specific questions ...

BUT ...

I strongly recommend that you read ALL of this book before you start working on this system ...

Thanks all of you for help. I think i can close the topic now