SLC500 connection methods

Hi,

first post - I've been in the electrical industry for 15 years, but recently I'm realising a long term ambition to be involved with PLCs. I keep reading this board, and its great for picking up ideas and tips.

I get help from my company who are training me up as and when time permits, but it tends to be what I need to know when I need to know it type stuff.

I've only been working with SLC5/05's but I've got some work coming up on 5/03 & 5/04 processors.

can someone help with a few questions:

I've bought a 1747-UIC connector, I know this is ok for 5/03's but can I use it to connect to a 5/04 and access other PLCs on the DH+ network?

The PLCs are connected up as follows:

DH+ to each processor, then DH485 out of the RS232 port to a AIC+ (mini D connector), this AIC+ links to a second AIC+ connector via DH485. The first AIC is connected to an HMI, and the second AIC has a spare 232 port for programming. There are about 10 PLCs also on the DH+ network.

I was talking to someone who I think suggested I could connect to the second AIC connector and then access all the PLCs on the DH+ network via DH485.

is the above correct? I just want to get into these 5/04s before I have to do one!


thanks for any help

Andy

Hi Andy and welcome to the Forum!

As your new enough to this I'll explain some basics so we're clear...

Data Highway Plus (DH+) is one type of communication network and protocol.
Data Highway 485 (DH-485) is another.

They are both relatively older serial networking architectures, but are still widely in use due to their large install base over the last couple of decades.

DH+ is generally considered where a larger outlay is required. It supports baud rates up 230kbaud, up to 10,000ft cabling and up to 64 nodes.

DH-485 is generally considered for smaller outlays. It supports up to 19.2kbaud, 4,000ft cabling and up to 32 nodes.

They are different communications protocols and cannot communicate directly with each other.

SLC modular controllers all provide two communication ports, with the exception of the SLC 5/04. One port is standard on each and the other unique. The standard port, Channel 0, is the serial DB9 port which is user configurable for a select few protocols such as DF1 or DH-485. The unique port on each, Channel 1, is fixed at its predefined protocol. The SLC 5/05 as you know provides an Ethernet RJ-45 port. The SLC 5/03 provides a DH-485 RJ-45 port. The SLC 5/04 provides both a DH+ 3-pin port and a DH+ 8-pin round mini-Din port.

The 1747-UIC is just for communications with DH-485 devices. You cannot use it to communicate directly with DH+ devices. It also does not support pass-thru from DH-485 devices to DH+ devices, such as an SLC 5/04 configured for pass-thru between its two ports.

Alternatively, without the 1747-UIC, you can also connect directly to an AIC and gain access to the DH-485 device or network, such as Channel 0 on an SLC 5/04 configured for DH-485. But from memory, I'm still not sure if you can pass-thru from the DH-485 to DH+ network using this connection? From what I can recall, the 5/04 pass-thru feature is only designed to work the other way i.e. Connect to DH+ and bridge to the DH-485 network. I know this works using a 1784-PCMK card because I have one that used to do just that before an SLC 5/04 was upgraded to a 5/05. You hardly have such a card knocking about?

Failing any attempts to make any of that work...

The equivalent to the 1747-UIC, only for DH+, is the 1784-U2DHP. This interface converter connects from USB to DH+ 8 pin mini-Din ports, such as on the SLC 5/04. This will give you full access to the DH+ network without disruption.

It is quite expensive compared to the 1747-UIC, so be prepared if pricing one up.

Regards,
George

Thanks for the help George, very helpful reply.

I work on a lot of different sites and many of them are on DH+, I like to buy my own equipment, but I might draw the line at the cost of one of those 1784-U2DHP connectors. My company will have to buy that!

Andy

For the SLC5/04, you can probably (*) connect to it via the CH0 port and DF1 protocol. You just need a plain serial port. If your laptop does not have a serial port, then a USB-to-serial adapter will do. DF1 is quite forgiving and will work with any (**) serial adapter.

*: DF1 is the default and most used protocol with this port, but there is the possibility that CH0 is set to DH485 or ASCII protocol.
**: No guarantee though.

You can do the same with the SLC5/03, but since you have a UIC adapter, then that is the best way to go.

Hi Jesper,

Thanks for your reply, I've had a look at some code from a few of these 5/04s and it looks like channel 0 has been set up as DH485 as a standard set up on them all.

I know I cant do it on these PLCs as the port is configured for DH485, but its interesting to know that I should be able to go through a USB to serial converter for DF1 when they're set up like that, I had assumed this wouldn't work (from what I've read before). I'm currently using a Dell laptop with XP on it, which has a serial port - but in time this will get replaced, so another useful bit of info there.... I've got an old PLC I use for practising with, so I'll have a go on that and give it a try.


Thanks


Andy

Andy1983 said:

I know I cant do it on these PLCs as the port is configured for DH485,

Click to expand...

In that case you should be able to use the UIC adapter, but with a serial null-modem cable to the CH0 port.

Andy1983 said:

but its interesting to know that I should be able to go through a USB to serial converter for DF1 when they're set up like that, I had assumed this wouldn't work (from what I've read before).

Click to expand...

Maybe you think about using a PIC adapter with a USB-to-serial cable. That wont work.
But DF1 does work. Have done it many times (since laptops no longer comes with PCMCIA slots, and my PCMK adapter is now an expensive museum relic).
At 19.2k or 38.4k DF1 runs really well. Much faster than DH485.

Yes, Channel 0 DF1 pass-thru to Channel 1 DH+ will work, but I was working off the assumption from the opening post that all the SLC 5/04 processors were set for DH-485 for Channel 0 and connected to AIC's and so could not be changed? But let's have a closer look at that...

Andy1983 said:

...DH+ to each processor, then DH485 out of the RS232 port to a AIC+ (mini D connector), this AIC+ links to a second AIC+ connector via DH485. The first AIC is connected to an HMI, and the second AIC has a spare 232 port for programming[/B]. There are about 10 PLCs also on the DH+ network...

Click to expand...

I assume the two SLC 5/04 with an AIC+ you have mentioned are done this way so they can communicate with the DH-485 HMI?

Are there only two SLC 5/04 with an AIC+ or do all of the other SLC 5/04 have one as well? It would be unusual to have them all linked on DH+ and also on DH-485, but not unheard of. If they all had to communicate with the HMI would be one reason, but a heavy comms load on it nonetheless.

In other words, are any of the other SLC 5/04's Channel 0 apparently unused? If so, then you could reconfigure a Channel 0 port for DF1 and go in that way, as Jesper has mentioned.

If not, and DH-485 is your only poison on Channel 0, then I still do not think you can use the UIC to go in DH-485 and bridge to DH+. I said earlier that it "...does not support pass-thru from DH-485 devices to DH+ devices, such as an SLC 5/04 configured for pass-thru between its two ports...".

The following would support this...

Rockwell said:

Pass-Thru and Bridging Capabilities

The 1747-UIC converter can NOT
•Produce the remote Data Highway-485 packets that are necessary to pass-thru from Data Highway-485 to DF1 on the SLC 5/03.

•Bridge through or see a Data Highway Plus network when interfaced with a DH-485 port on a 1785-KA5 module.

The 1747-UIC converter is a serial DF1 to Data Highway-485 protocol converter and since DF1 is not capable of initiating remote/bridging packets (PCCC packets that include the Data Highway remote header with source and destination link IDs), there is no way for the RSLinx Classic software to initiate a remote packet to bridge through the KA5 or pass-thru a SLC.

Click to expand...

This would suggest that the UIC is a non runner, but I have seen literature incorrect before. I've never attempted it so I cannot be concrete sure without testing, but I don't have an SLC 5/04 to play with any more.

It would also contradict the fact that DF1 pass-thru to DH+ is supported on these controllers to browse all nodes, albeit direct DF1 without the UIC.

All reading I've done so far suggests that the following is supported for the SLC 5/04...

CH 0 DF1 to CH 1 DH+ pass-thru
CH 1 DH+ to CH 0 DH-485 pass-thru

...but not supported is...

CH 0 DH-485 to CH 1 DH+ pass-thru

Jesper,

Have you specifically done it before, with a DH-485 1747-UIC in thru CH 0, I mean? Can you say for certain that it works? I'm just not sure?

Regards,
George

Geospark said:

I assume the two SLC 5/04 with an AIC+ you have mentioned are done this way so they can communicate with the DH-485 HMI?

Are there only two SLC 5/04 with an AIC+ or do all of the other SLC 5/04 have one as well? It would be unusual to have them all linked on DH+ and also on DH-485, but not unheard of. If they all had to communicate with the HMI would be one reason, but a heavy comms load on it nonetheless.

In other words, are any of the other SLC 5/04's Channel 0 apparently unused? If so, then you could reconfigure a Channel 0 port for DF1 and go in that way, as Jesper has mentioned.

Click to expand...

Hi

in the example I used in my first post we have a series of control panels, all linked with DH+ directly to each processor, each control panel has a single PLC in it. from what I can understand all the channel 0 connections are configured as DH485, and link down to an AIC+, as you suggest this seems to be primarily used for connecting to a panelview HMI.

Where I've probably confused you is in the particular control panel I described in the first post, there are 2 AIC+ connectors, the first one is for the HMI (using the RS 232 Port), and the second is linked from the first via DH485, and has a spare RS232 port. there is a drawing of this on the site which shows this spare RS232 port as being for programming.

This is why I wondered if it had been designed to allow you to bridge into the DH+ network, or if it was solely for programming the associated PLC without having to disconnect the HMI from the first AIC+.


From what has been said in yours and Jespers posts above, I'm starting to understand it better, I guess you have to go and sit at each PLC with a DH485 connection, rather than what I've been doing with SLC5/05s which is sitting in the control room and remotely connecting over ethernet to each PLC on the network in turn.


Andy

Ok, it's getting clearer, but are you saying that only the two AIC+ in your example are networked together via the 6-pin phoenix plugs in that one panel and all the others are standalone in the other panels to just connect the SLC 5/04 to a local PanelView?

That is, are all the AIC+ connected together or not, forming a DH-485 network?

If they were then this, I'm sure, would have been the intended network to browse in to. You would go in through the spare AIC+ port and could then access the local controller CH 0 or HMI or alternatively, browse the DH-485 network to access the other controllers on CH 0 or their local HMI. The DH+ network would just be used for operational communications between controllers.

If so, then you would not need access to the DH+ network to communicate with any of the controllers or any of the HMI. Only if there was a DH+ node(s) not transparent to the DH-485 network would you have to communicate with the DH+ network to reach them.

But that all hangs on whether the DH-485 network is present or not. I'm thinking not?

Also, to connect locally to each AIC+, would you not have to unplug the HMI or controller to free a port to browse in?

Whether through a direct DH-485 network or pass-thru to DH+, that second AIC+ in that panel does appear to have been installed to access "a" network. If not DH-485 direct, then I would not rule out the pass-thru option until you or someone else can test or confirm whether it is possible or not.

Regards,
George

Your right George, those two AIC+ Connectors are the only ones networked together.

I suspect the panel with the two AIC+ connectors is a late addition designed to make it easier to work on that particular PLC.

From reading through your info and after talking to someone at work with more experience than me - I don't think you can access the DH+ network using the processor and AIC as a pass through.

It was a nice idea though!

Andy