A few questions.

We have a slc500 plc that controls a sample system. Today, we found out that one of the motors had a lead burn into inside of some conduit. Around the same time we noticed this, the plc processor keeps flashing a fault light.

It is a slc 5/03.

I was going to see if it was possible to go online with the plc and upload the logic on a pc and try to save it in case the processor needs to be replaced. The only port on the processor is a rj45 connector. I was curious on how someone would connect to this ? I wouldnt imagine it is as simple as a cat45 cable with rj45 ends.


Sorry for the questions on the holidays.

The RJ45 connector is not ethernet, it is DH485, you will need a communication adapter to use it. Below the RJ45 connector there is a DB9 connector, it is RS-232. I would suggest you use that to check the processor.
You will need a USB to RS232 adapter, null modem cable and software, RSLinx and RSLogix 500.

Im pretty sure I got the model number right, but this processor doesnt have a DB9 connector. It only has a rj45 port.

Open the hinged door on the CPU and post the part number - e.g. one behind me is 1747-L542 (SLC 5/04).

Do NOT plug an ethernet cable into it - you will blow the port on your laptop.

HoldenC said:

Im pretty sure I got the model number right, but this processor doesnt have a DB9 connector. It only has a rj45 port.

Click to expand...

It´s probably an older 5/01 or similar with the rechargable battery and the RJ45 style connector but no DB9.
Doesn´t that require a 1747-PIC comms adaptor - please correct me if I´m wrong.

I prefer it when there is a DB9 as a CP3 cable is very easy to build and it´s easy to configure the comms.

Ill go over today and get the model number.

I was thinking the same. It's either a 5/01 or a 5/02 processor.

For these processors the RJ45 port is Channel 1 and is a fixed DH-485 protocol communications port.

ncjunk said:

...Doesn´t that require a 1747-PIC comms adaptor...

Click to expand...

ncjunk,

The 1747-PIC is of course an option, if you have one, but if a user does not already have any DH-485 interface then...

HoldenC,

You would need a 1747-UIC interface and 1747-C13 cable to communicate with your computer. This is a USB to DH-485 interface, which in essence replaced the 1747-PIC. It can connect to DH-485 devices via either RS-232 or RS-485 wiring. For the RJ45 port on an SLC it is using RS-485 wiring.

But also...

If the processor's "CPU FAULT" LED is flashing then it is possible that the fault condition, be it a short, or a surge, or whatever might have reached the PLC Chassis and caused some hardware damage. If not, the CPU may still have experienced a Major Fault and cleared its memory. If it has, then you will not be able to retrieve the program. But it may also have a recoverable error too.

Regards,
George

Does it look like this?...

Thanks for all the help.

That is exactly what it looks like.

Yes there are a few options for this, I got the PIC cheap chinese version off of ebay, They also do a usb to rs-485 to pic cable.
Both options are very cheap - I got one just for the odd job that turns up where the machines died and they need it back up and running a.s.a.p.

I wanted to thank you all for the replies. The holidays slowed me down on replaying back.

I was looking at the 1747-uic, and the 1747-c13. I just had a couple questions.

On the 17r7-uic, does it allow you to connect a serial cable or a rj45 connector ? Or am I missing the way it should connect.

Lastly, on the 1747 c13, is it just a cat5 or 6 cable? If so, is it straight through, or crossover ?

Get the 1747-UIC connect the cat5 cable to the ports that's how it works with 5/03. If you get a 1747-UIC make sure the switch is in the DH485 position.

HoldenC said:

I was looking at the 1747-uic, and the 1747-c13. I just had a couple questions.

On the 17r7-uic, does it allow you to connect a serial cable or a rj45 connector ? Or am I missing the way it should connect.

Lastly, on the 1747 c13, is it just a cat5 or 6 cable? If so, is it straight through, or crossover ?

Click to expand...

We offer both and our version of the UIC http://www.plccable.com/search.php?search_query=1747-uic&x=0&y=0

See here for the procedure http://www.plccable.com/comm-support-videos/ its the top link

If you use a real UIC make sure you dont use a cross over cat cable you will burn up the UIC as the 5/02 has 24vdc on the RJ45 port

RJ45 is not automatically Ethernet; it is simply a connector jack...

HoldenC said:

...the 1747-uic, does it allow you to connect a serial cable or a rj45 connector ?...

Click to expand...

As I explained...

Geospark said:

...You would need a 1747-UIC interface and 1747-C13 cable...This is a USB to DH-485 interface...It can connect to DH-485 devices via either RS-232 or RS-485 wiring. For the RJ45 port on an SLC it is using RS-485 wiring.

Click to expand...

...for the 1747-UIC you have two options for connecting to DH-485 protocol configured devices. Its 9-pin standard serial port is its RS-232 port and is of course using RS-232 wiring. Its 8-pin RJ45 port is its RS-485 port and is of course using RS-485 wiring. Both ports "talk" the DH-485 protocol language, but use different wiring standards to communicate. So you have the option of using either the RS-232 (DH-485) port or the RS-485 (DH-485) port.

So you use whichever port is required to connect to the DH-485 device at hand. In your case, as it's an SLC native DH-485 port (RJ45); you use the RS-485 (DH-485) port on the 1747-UIC with a 1747-C13 cable (RJ45 - RJ45).

HoldenC said:

...the 1747 c13, is it just a cat5 or 6 cable? If so, is it straight through, or crossover ?

Click to expand...

I would like to categorically answer these two questions as "No" & "No", in case you are now thinking it's as good as a straight through Ethernet cable.

The 1747-C13 closely resembles an Ethernet cable, and a straight through Ethernet cable at that. But it is not.

A straight through Ethernet cable has all 8 pins populated straight through from 1-1 through 8-8. The 1747-C13 has all pins populated straight through except pins 3-3 ( BROWN +24 VDC) and 6-6 (DRAIN EARTH GND). These two are missing.

While the 1747-C13 cable having these pins missing is more to do with the cable not being able to do certain "AB things", it is still important to make this distinction here.

As has been pointed out to you, you should never use an Ethernet crossover cable with the UIC interface. The RS-485 (DH-485) port on the UIC will be irreparably damaged if connected to certain devices.

Also, one cannot foretell all of the DH-485 capable devices that one might connect the 1747-UIC interface.

For these reasons, I would always advise users to NOT get into the habit of using Ethernet cable replacements where it is expressly stated by AB to NOT do so. This is not because they want to sell you more cables, but more to save your equipment in the future.

It is too easy for users to have a couple of Ethernet cables in the "bag" and quickly whip one out when in a hurry, whenever they see an RJ45 port, without thinking first. One could grab a crossover cable all too easily. If you are always thinking "...sure it's OK...if this Ethernet cable doesn't work I'll just grab another until it does work..." then you run the risk of doing harm.

Whereas, if you start out with the thinking that you must use the correct cable with 1747-UIC, and know it to be the 1747-C13, or equivalent, then you should not go wrong.

I say equivalent because you can also use any other equivalent AB cable, or indeed make your own.

While an Ethernet straight through cable may be used to replace the 1747-C13 cable when used with the 1747-UIC and certain devices, such as SLC controllers, there may be situations where the pins 3-3 and 6-6 could potentially connect two devices together in a manner unintended.

If purchasing a 1747-UIC, or some of the very good alternatives, such as Mark's (geniusintraining), then I would always recommend you also purchase and have the 1747-C13, or equivalent alternative to hand.

Regards,
George