Ethernet/IP with Micrologix 1200

[crsgab 0]

Hi: We are working on a project, we have 10 workbenchs where motors are assembled , each one has a Micrologix 1200 with a 1761-NET-ENI . We want to install a sensor system to detect when operator takes material from some containers, if material is not taken one alarm will sound and a red ligth on bench will turn on to advise supervisor , but we want to put just one alarm for the 10 workbenchs . As the site where we want to install this alarm is away from workbenches we thougth maybe we could put another PLC with ethernet to turn on the alarm ,because if we decide to wire cables from workbenches to alarm place would be more difficult and expensive. But now I wonder how each PLC would send a signal every time the operator forget to take material to PLC which controls the alarm to turn it on. I was reading that MSG instruction is used to send messages to a specific node over ethernet, but I don't know if there is an easiest way to do this. I haven't used this instruction so I don't know what would happen if for example 2 or more workbenches send a message to turn on the alarm , if the PLC would receive each one of messages. We are still cheking details so we are opened to suggestions. Thanks in advance Gabriel

[BobLfoot 301]

Dear Gabriel: In the examples below I assume that your 1761-NET-ENI are congured according to the manual to send the message to the proper ENI Node to hit the other PLC. Sample ENI Configuration SCHEME - Can be used in all ENI's Assumes the subnet in use is 192.168.1.XX Address Node 0 thru Node 100 to 192.168.1.100 Address Node 1 thru Node 101 to 192.168.1.101 Address Node 2 thru Node 102 to 192.168.1.102 Address Node 3 thru Node 103 to 192.168.1.103 Address Node 4 thru Node 104 to 192.168.1.104 Address Node 5 thru Node 105 to 192.168.1.105 Address Node 6 thru Node 106 to 192.168.1.106 Address Node 7 thru Node 107 to 192.168.1.107 Address Node 8 thru Node 108 to 192.168.1.108 Address Node 9 thru Node 109 to 192.168.1.109 Address Node 10 thru Node 110 to 192.168.1.110 Assign ENI Addresses as Follows; PLC 0 - 192.168.1.100 PLC 1 - 192.168.1.101 PLC 2 - 192.168.1.102 PLC 3 - 192.168.1.103 PLC 4 - 192.168.1.104 PLC 5 - 192.168.1.105 PLC 6 - 192.168.1.106 PLC 7 - 192.168.1.107 PLC 8 - 192.168.1.108 PLC 9 - 192.168.1.109 PLC 10 - 192.168.1.110 For the sake of my example I will assume that you have not used the data files I mention but If you have then replace them with another unused number of data file. For this example assume PLC's 1 thru 10 are on the workbench and PLC 0 is the master. CREATE DATA TABLES NEEDED In all 11 PLC's create the Data File N17 of size 128. and Data File N27 of size 128. Also create a MG file of size 32. ADD A MSG READ OF MASTER TO EACH BENCH PLC In PLC 1 add a MSG instruction to node 0 which reads N17:10 from PLC 0 for 10 integers use MG 0 for control. In PLC 2 add a MSG instruction to node 0 which reads N17:20 from PLC 0 for 10 integers use MG 0 for control. In PLC 3 add a MSG instruction to node 0 which reads N17:30 from PLC 0 for 10 integers use MG 0 for control. In PLC 4 add a MSG instruction to node 0 which reads N17:40 from PLC 0 for 10 integers use MG 0 for control. In PLC 5 add a MSG instruction to node 0 which reads N17:50 from PLC 0 for 10 integers use MG 0 for control. In PLC 6 add a MSG instruction to node 0 which reads N17:60 from PLC 0 for 10 integers use MG 0 for control. In PLC 7 add a MSG instruction to node 0 which reads N17:70 from PLC 0 for 10 integers use MG 0 for control. In PLC 8 add a MSG instruction to node 0 which reads N17:80 from PLC 0 for 10 integers use MG 0 for control. In PLC 9 add a MSG instruction to node 0 which reads N17:90 from PLC 0 for 10 integers use MG 0 for control. In PLC 10 add a MSG instruction to node 0 which reads N17:100 from PLC 0 for 10 integers use MG 0 for control. ADD A MSG READ OF EACH BENCH PLC FROM MASTER In PLC 0 add a MSG instruction to node 1 which reads N27:10 from PLC 1 for 10 integers use MG 0 for control. In PLC 0 add a MSG instruction to node 2 which reads N27:20 from PLC 2 for 10 integers use MG 2 for control. In PLC 0 add a MSG instruction to node 3 which reads N27:30 from PLC 3 for 10 integers use MG 4 for control. In PLC 0 add a MSG instruction to node 4 which reads N27:40 from PLC 4 for 10 integers use MG 6 for control. In PLC 0 add a MSG instruction to node 5 which reads N27:50 from PLC 5 for 10 integers use MG 8 for control. In PLC 0 add a MSG instruction to node 6 which reads N27:60 from PLC 6 for 10 integers use MG 10 for control. In PLC 0 add a MSG instruction to node 7 which reads N27:70 from PLC 7 for 10 integers use MG 12 for control. In PLC 0 add a MSG instruction to node 8 which reads N27:80 from PLC 8 for 10 integers use MG 14 for control. In PLC 0 add a MSG instruction to node 9 which reads N27:90 from PLC 9 for 10 integers use MG 16 for control. In PLC 0 add a MSG instruction to node 10 which reads N27:100 from PLC 10 for 10 integers use MG 18 for control. NOTES ABOUT MSG ENABLE CONDITIONS Note In PLC 0 you'll want some logic to trigger the MSG's one after the other in PLC's 1 thru 10 they can trigger continuously. ADD RUNGS FOR MESSAGE ERROR REPORTING TO HMI APPLICATION IF PRESENT IN EACH BENCH PLC In PLC 1 add rungs as follows - Note order is important: SOR XIC N17:10/0 XIC N27:10/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:10/0 OTE N27:10/0 EOR In PLC 2 add rungs as follows - Note order is important: SOR XIC N17:20/0 XIC N27:20/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:20/0 OTE N27:20/0 EOR In PLC 3 add rungs as follows - Note order is important: SOR XIC N17:30/0 XIC N27:30/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:30/0 OTE N27:30/0 EOR In PLC 4 add rungs as follows - Note order is important: SOR XIC N17:40/0 XIC N27:40/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:40/0 OTE N27:40/0 EOR In PLC 5 add rungs as follows - Note order is important: SOR XIC N17:50/0 XIC N27:50/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:50/0 OTE N27:50/0 EOR In PLC 6 add rungs as follows - Note order is important: SOR XIC N17:60/0 XIC N27:60/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:60/0 OTE N27:60/0 EOR In PLC 7 add rungs as follows - Note order is important: SOR XIC N17:70/0 XIC N27:70/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:70/0 OTE N27:70/0 EOR In PLC 8 add rungs as follows - Note order is important: SOR XIC N17:80/0 XIC N27:80/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:80/0 OTE N27:80/0 EOR In PLC 9 add rungs as follows - Note order is important: SOR XIC N17:90/0 XIC N27:90/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:90/0 OTE N27:90/0 EOR In PLC 10 add rungs as follows - Note order is important: SOR XIC N17:100/0 XIC N27:100/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIC N17:100/0 OTE N27:100/0 EOR ADD RUNGS FOR MESSAGE ERROR REPORTING TO HMI APPLICATION IF PRESENT IN MASTER PLC And Finally in PLC 0 add the following rungs - Note Order is Important. -- For PLC 1 SOR XIO N17:10/0 XIC N27:10/0 TON T4:10 0.01 500 EOR SOR BST XIC T4:10/DN NXB XIC MG0.ER BND OTE B3:10/0 EOR NOTE B3:10/0 IS THE PLC 1 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:10/0 OTE N17:10/0 EOR -- For PLC 2 SOR XIO N17:20/0 XIC N27:20/0 TON T4:11 0.01 500 EOR SOR BST XIC T4:11/DN NXB XIC MG2.ER BND OTE B3:10/1 EOR NOTE B3:10/1 IS THE PLC 2 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:20/0 OTE N17:20/0 EOR -- For PLC 3 SOR XIO N17:30/0 XIC N27:30/0 TON T4:12 0.01 500 EOR SOR BST XIC T4:12/DN NXB XIC MG4.ER BND OTE B3:10/2 EOR NOTE B3:10/2 IS THE PLC 3 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:30/0 OTE N17:30/0 EOR -- For PLC 4 SOR XIO N17:40/0 XIC N27:40/0 TON T4:13 0.01 500 EOR SOR BST XIC T4:13/DN NXB XIC MG6.ER BND OTE B3:10/3 EOR NOTE B3:10/3 IS THE PLC 4 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:40/0 OTE N17:40/0 EOR -- For PLC 5 SOR XIO N17:50/0 XIC N27:50/0 TON T4:14 0.01 500 EOR SOR BST XIC T4:14/DN NXB XIC MG8.ER BND OTE B3:10/4 EOR NOTE B3:10/4 IS THE PLC 5 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:50/0 OTE N17:50/0 EOR -- For PLC 6 SOR XIO N17:60/0 XIC N27:60/0 TON T4:15 0.01 500 EOR SOR BST XIC T4:15/DN NXB XIC MG10.ER BND OTE B3:10/5 EOR NOTE B3:10/5 IS THE PLC 6 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:60/0 OTE N17:60/0 EOR -- For PLC 7 SOR XIO N17:70/0 XIC N27:70/0 TON T4:16 0.01 500 EOR SOR BST XIC T4:16/DN NXB XIC MG12.ER BND OTE B3:10/6 EOR NOTE B3:10/6 IS THE PLC 7 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:70/0 OTE N17:70/0 EOR -- For PLC 8 SOR XIO N17:80/0 XIC N27:80/0 TON T4:17 0.01 500 EOR SOR BST XIC T4:17/DN NXB XIC MG14.ER BND OTE B3:10/7 EOR NOTE B3:10/7 IS THE PLC 8 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:80/0 OTE N17:80/0 EOR -- For PLC 9 SOR XIO N17:90/0 XIC N27:90/0 TON T4:18 0.01 500 EOR SOR BST XIC T4:18/DN NXB XIC MG16.ER BND OTE B3:10/8 EOR NOTE B3:10/8 IS THE PLC 9 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:90/0 OTE N17:90/0 EOR -- For PLC 10 SOR XIO N17:100/0 XIC N27:100/0 TON T4:19 0.01 500 EOR SOR BST XIC T4:19/DN NXB XIC MG18.ER BND OTE B3:10/9 EOR NOTE B3:10/9 IS THE PLC 10 MESSAGE HAS AN ERROR BIT FOR YOUR HMI APPLICATION SOR XIO N27:100/0 OTE N17:100/0 EOR ADD THE LOGIC TO SEND THE BENCH ALARM BIT TO THE MASTER In PLC 1 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:10/15 XIO N17:10/15 BND OTE N27:10/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:10/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 2 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:20/15 XIO N17:20/15 BND OTE N27:20/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:20/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 3 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:30/15 XIO N17:30/15 BND OTE N27:30/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:30/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 4 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:40/15 XIO N17:40/15 BND OTE N27:40/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:40/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 5 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:50/15 XIO N17:50/15 BND OTE N27:50/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:50/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 6 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:60/15 XIO N17:60/15 BND OTE N27:60/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:60/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 7 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:70/15 XIO N17:70/15 BND OTE N27:70/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:70/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 8 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:80/15 XIO N17:80/15 BND OTE N27:80/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:80/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 9 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:90/15 XIO N17:90/15 BND OTE N27:90/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:90/15 IS THE MASTER PLC ALARM RESET BIT. In PLC 10 add rungs as follows -- SOR BST XIC B3:0/0 NXB N27:100/15 XIO N17:100/15 BND OTE N27:100/15 EOR NOTE B3:0/0 IS THE BENCH PLC INTERNAL ALARM BIT NOTE N17:100/15 IS THE MASTER PLC ALARM RESET BIT. ADD THE LOGIC TO SEND RESET THE BENCH ALARM BIT FROM THE MASTER FOR PLC 1 ADD SOR XIC N27:10/15 BST XIC B3:0/1 NXB XIC N17:10/15 BND OTE N17:10/15 EOR NOTE B3:0/1 IS THE RESET PLC 1 ALARM BIT FROM HMI FOR PLC 2 ADD SOR XIC N27:20/15 BST XIC B3:0/2 NXB XIC N17:20/15 BND OTE N17:20/15 EOR NOTE B3:0/2 IS THE RESET PLC 2 ALARM BIT FROM HMI FOR PLC 3 ADD SOR XIC N27:30/15 BST XIC B3:0/3 NXB XIC N17:30/15 BND OTE N17:30/15 EOR NOTE B3:0/3 IS THE RESET PLC 3 ALARM BIT FROM HMI FOR PLC 4 ADD SOR XIC N27:40/15 BST XIC B3:0/4 NXB XIC N17:40/15 BND OTE N17:40/15 EOR NOTE B3:0/4 IS THE RESET PLC 4 ALARM BIT FROM HMI FOR PLC 5 ADD SOR XIC N27:50/15 BST XIC B3:0/5 NXB XIC N17:50/15 BND OTE N17:50/15 EOR NOTE B3:0/5 IS THE RESET PLC 5 ALARM BIT FROM HMI FOR PLC 6 ADD SOR XIC N27:60/15 BST XIC B3:0/6 NXB XIC N17:60/15 BND OTE N17:60/15 EOR NOTE B3:0/6 IS THE RESET PLC 6 ALARM BIT FROM HMI FOR PLC 7 ADD SOR XIC N27:70/15 BST XIC B3:0/7 NXB XIC N17:70/15 BND OTE N17:70/15 EOR NOTE B3:0/7 IS THE RESET PLC 7 ALARM BIT FROM HMI FOR PLC 8 ADD SOR XIC N27:80/15 BST XIC B3:0/8 NXB XIC N17:80/15 BND OTE N17:80/15 EOR NOTE B3:0/8 IS THE RESET PLC 8 ALARM BIT FROM HMI FOR PLC 9 ADD SOR XIC N27:90/15 BST XIC B3:0/9 NXB XIC N17:90/15 BND OTE N17:90/15 EOR NOTE B3:0/9 IS THE RESET PLC 9 ALARM BIT FROM HMI FOR PLC 10 ADD SOR XIC N27:100/15 BST XIC B3:0/10 NXB XIC N17:100/15 BND OTE N17:100/15 EOR NOTE B3:0/10 IS THE RESET PLC 10 ALARM BIT FROM HMI Man this is long post hope I made no typos. Hope it gives you the idea.

[crsgab 0]

Thanks a lot , I'm going to check your example.. I'm lost on this: where do I set up the node number for IP's? I mean, I have 11 PLC's with a specific IP address and I guess I have to specify this address to a node number on ENI/ENIW utility? but on each 1761-NET-ENI do I have to specify the 11 IP's address on the message routing tab? Tomorrow I"ll start to set up this modules but I'm not sure if this is the correct way to configure the nodes. Any help will be apreciated. Best regards Gabriel

[BobLfoot 301]

Assuming you are connecting to the ENI Serially for Configuration , You will need to set up an ENI configuration as follows for all ENI's: Refer to Manual Page 42 and set up the COM Port Settings to match your needs. Refer to Page 43 and enter the IP assigned to that PLC. I would advise turning BootP off, but this is a personal preference. Refer to page 45 and the the message routing IP's according to the example I gave. Node 0 to PLC 0. Node 1 to PLC 1, ... etc. Once you have created and saved the configuration for PLC 0 creating PLC 1 is easy because only the IP assigned is going to change. The COM Port and Message Routing will be the same for all 11 ENI's. Looking over my previous post I should also point out that you have nine integers in each PLC reserved to Send Data to PLC 0 and nine Integers in each PLC reserved to receive data from PLC 0 in the future. For Example N17:11 thru N17:19 and N27:11 thru N27:19 betweem PLC 0 and PLC 1. For Example N17:21 thru N17:29 and N27:21 thru N27:29 betweem PLC 0 and PLC 2. .... For Example N17:101 thru N17:109 and N27:101 thru N27:109 betweem PLC 0 and PLC 10. You have 14 Binaries in each PLC reserved to Send Data to PLC 0 and 14 Binaries in each PLC reserved to receive data from PLC 0 in the future. For Example N17:10/1 thru N17:10/14 and N27:10/1 thru N27:10/14 betweem PLC 0 and PLC 1. For Example N17:20/1 thru N17:20/14 and N27:20/1 thru N27:20/14 betweem PLC 0 and PLC 2. .... For Example N17:100/1 thru N17:100/14 and N27:100/1 thru N27:100/14 betweem PLC 0 and PLC 10. You can use these for later communication needs when they arise and they will. FYI - Here is the Message Plan I laid down. ML1200_ENI_Plan.zip

[Ken Roach 194]

This isn't going to work with only 1761-NET-ENI devices. The -ENI is intended to allow access to just the one controller from a small number of network stations. It supports only six TCP connections at the same time; two incoming, two outgoing, and two either way. Your architecture is fine for an HMI system where a single computer or operator interface terminal communicates with 10 MicroLogix controllers, or where a ControlLogix or SLC-5/05 communicates with 10 MicroLogix controllers. It's just that another MicroLogix/NET-ENI can't be the central point. Were these Net-ENI's installed to just provide RSLogix 500 access to the controllers, or is there an HMI or other central device communicating with them already ?

[BobLfoot 301]

So PLC 0 can't be a Micrologix with and ENI it needs to be a CLGX or SLC 5/05. Otherwise is the plan sound Ken or did I miss another fine point.

[crsgab 0]

Hi: We don't have an HMI neither a central device. Since I started working here this workbenches have the 1761-net-eni and are used to provide acces to Rslogix PLC program with the wireless network we have inside the company. If I understood , you mean I have to use a contrologix or SLC/05 as a central point? As I said yesterday we still are checking some details so I haven't purchased the central PLC and I'm still on time to make necessary changes. Your suggestions are very apreciated. Best regards Gabriel

[BobLfoot 301]

My personal Preference for a Central PLC in this case would be a ControlLogix CPU. Run the following past you AB Rep but I'd outfit with the following: 1. 1756A4 - Four Slot Rack 2. 1756PA72 - Power Supply 3. 1756L61 - CPU 4. 1756ENBT - Ethernet Adapter Of course you'll need to buy RSLogix 5000 to program it.

[TimWilborne 108]

I would widen that rack up a little bit. 7 or 10 slot. I did something like this and was using 5 ethernet modules

[BobLfoot 301]

Question for some other guru's. Option A Could this work with a MicroLogix as the Central Processor if all messages where moved to PLC 0. I.E. Read MSGs in PLC 1-10 would need to be Write MSGs in PLC 0. And then a sequencer would trigger only 2 messages at a time and not exceed to MSG connection limit. Option B Could the Reads be Cascaded N17 read from 0 to 1, then 1 to 2, 2 to 3 etc. Also could the N27 reads be cascaded read 10 from 9, 9 from 8 and etc. Note to Original Poster - These may work but they are less ideal than using an SLC ot CLGX as PLC 0.

[Ken Roach 194]

You and I must be reading the same books, Bob; those are both of the ideas that I ran down when thinking about this problem. Option 1 won't work because the TCP connection doesn't get closed immediately when a message instruction completes. It has to time out from inactivity, and that timeout is part of the embedded TCP stack and isn't configurable by the MicroLogix programmer. My recollection is that the timeout is 30 seconds. This isn't unique to the Net-ENI or to A-B; it's a totally standard part of most TCP/IP Ethernet implementations. Option 2 would work in theory, but in practice one of the benches is likely to be disconnected at some point, and the complexity is pretty high. Also the data array could end up exceeding the message size limit (I think it's 120 words for DF1). I would recommend an SLC-5/05 as the central station, because he already has RSLogix 500 and because the 5/05 can handle 16 simultaneous incoming TCP connections (some models can handle 24; I will check).

[BobLfoot 301]

Ken - How does N17:10 thru N17:109 which is 110 elements exceed 120? Same question applies to N27 as only elements 10 thru 109 are needed for communications.

[Ken Roach 194]

I didn't read and count your data elements, Bob; I was just commenting from experience where a system that's close to it's maximum ends up getting expanded and overrunning its capacity, even when you allowed for expansion. A more significant consideration, I think, would be what happened when one of the controllers in the fire brigade was powered down and unable to forward the information. Installations like this I tend to see the need for message displays and data logging and so forth so I usually see a PC or EOI at the head end.

[BobLfoot 301]

On That we agree Ken. The Original Poster definitely needs to consider an HMI associated with the Master PLC.

[crsgab 0]

Hi: We decided to use a SLC 5/05. Regarding to use a HMI , I have the Ingear ActiveX control , do you think could be useful for this application? At first we didn't plan to use it on this project but reading your comments maybe could be a choice. Regards

[BobLfoot 301]

All depends on what your end user expects. Will they want a log of alarms and when the occurred. Not a must but if affordable worth including.

[crsgab 0]

Hi!! Well after several days for tests I have finished and my aplication is working as I wanted But my question is this as I really spent lot of time because of this detail. I used a SLC 05 as a central point, and when you have to configure the msg instruction you have the option of Multihop. At first I didn't use it but I had a lot of trouble as I get error on MSG instructions, I got this: connection was broken. When I change to multihop everything started to work. I just wanna know what is the difference as I have look information for this topic but I haven't understood at all. Thanks for your suggestions, without them I coudn't have finished. Best regards. Gabriel

[Ken Roach 194]

The SLC-5/05 can use both the older A-B proprietary "CSPv4" Ethernet protocol, or the newer "EtherNet/IP" protocol. The 1761-NET-ENI only supports the newer EtherNet/IP protocol. In the MSG instruction configuration, configuring a "Multi-Hop" message causes the SLC-5/05 to use EtherNet/IP. A non-"Multi-Hop" message will use CSPv4, which allows it to communicate with older PLC-5E and SLC-5/05 controllers.