Thread Starter

Max Richey

This option appears Greek to me for several reasons. I am unable to thoroughly conceive of the impact that a device such as the Lantronics DR1 will have in my specific, albeit usual, application/scenario. Given the following:

3 Mitsubihi A series PLC's
3 TI 505/545 PLC's
1 Allen Bradley PLC 5/25 PLC
2 SLC 150's
1 Micrologix 1000
2 Unico VS Drive control racks
3 Motorola Arcnetted STD Bus racks
several discrete VS drives
1 very antiquated 6800 CPU driven rack with TTL I/O

I can hook to the Mitsubishi's and the TI's by way of Ehternet, but must purchase cards. I can hook serally now. Either case requires divers/OPC servers, but less significant is the serial option. The AB will need a new CPU and sidecar module to speak Ehternet. The others? well let's just say I'll have to pray about that.

For now, I know that serial connectivity is a must in some cases. RS232 and 485 will most ceratinly be employed at varying junctures. This tells me that no matter how fast I want the Ethernet connectivity to make my PLC's talk to me, I will be bottlenecked because my HMI will have to slow down(<10Mbps)for the serial devices.

My thought is that instead of Ethernet Cards, the Mits's, TI's and AB's could probably be packaging the serial data via encapsulation devices such as the Lantronics DR1 during the bottlenecked period. Then, the data can be subsequently accessed without significantly reducing the overall loop time of the HMI.

Bottom line: Is it worth spending $15K on cards and drivers in this case. I'm going to be slowed down anyway, so why not hook everything such that I am stuffing all the time rather than stuff and pump. You tell me. Is it worth $15k to pump occassionally?
From: Max Richey <[email protected]>

>3 Mitsubihi A series PLC's
>3 TI 505/545 PLC's
>1 Allen Bradley PLC 5/25 PLC
>2 SLC 150's
>1 Micrologix 1000
>2 Unico VS Drive control racks
>3 Motorola Arcnetted STD Bus racks
>several discrete VS drives
>1 very antiquated 6800 CPU driven rack with TTL I/O

You're a braver man than I, Max.

I think after fully accounting for maintenance costs, you have a strong engineering case for nuking the whole thing.

Jay Kirsch
Thanks Jay,

I feel the same way. Unfortunately, I don't have that option. As you may have surmised. I am a newbie to the SI realm. Just how does one go about making an intelligent forecast of SI/HMI maintenance costs?

Just to list a few of the costs:

You need to buy, and to some extent, keep your software up-to-date. You have 4 or 5 drivers to buy for the HMI package. Depending on which one you select they could cost from $500 to $2000 each. Do HMI drivers exist for the Motorola equipment ?

You have PLC programming software to maintain for each type of controller. These packages cost from $500 to ~$5000 each. The learning curve for all of this is horrendous. Budget three to four days of your time for each programming package just to get a sense of how to trouble-shoot the existing programs.

The Lantronix box should work with this, TI's NITP protocol uses intercharater timeouts. You should confirm that this is not going to be problem with the DR1. A-B has a similar box that converts A-B ethernet to DF1 protocol.

It is not possible for me to estimate your time. But if I had to take a GUESS at what I would do, here you go:

1) Replace the 6800 and STD stuff with MicroLogix w/ ethernet
2) Upgrade existing MicroLogix to same w/ ethernet
3) Upgrade SLC150 to MicroLogix
4) Use 1761-NET-ENI to bring the PLC5 on ethernet. (that's a tough call, it might be cheaper to go to Micrologix here too. )
5) Use CTI network card or Lantronix DR1 to bring TI's on ethernet
6) It sounds like the drives are wired to PLC's, if so, leave them alone
7) I don't know anything about Mitsubishi PLC's so I can't say.

You're down to three supportable PLCs this way. You should be able to get some help from an A-B / Siemens-TI / Mitsubishi application engineers on this too.

Good Luck,

Jay Kirsch
[email protected] <mailto:[email protected]>
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