Jimmie_Ohio
Member
After viewing the posts of others and helping whenever I could, it's time for me to post a topic and get some free advice. But then again, you get what you pay for...
I have a project to design that is similar to another one that I did a few years ago without any problems.
On the new project, I am proposing the PLC to be a SLC5/04 (catalog # 1747-L542). I am also using a PanelView 1000 color (catalog # 2711-K10C8). My old project was the same processor, except I used a smaller, monochrome PV550 (catalog # 2711-B5A8).
I'm not sure how far away these will be from each other yet. (I'm questioning the customer, but it shouldn't be more than 100' apart.) Last time I hooked these up via DH+ (blue hose) on CH0, the PLC was probably only 40-50 feet away from the PanelView. I'd like to do the same on the new project.
Now to the part in which I'm not completely sure... (DISCLAIMER: I know nothing about Modbus).
The project's specification wanted Modbus communication available to tie in to "the plant DCS" (distributed control system). To satisfy that specification at the quoting stage, I "googled" the topic, found a ProSoft InRax MVI46-MCM Modbus Communications Interface Module for SLC, and figured on throwing it in my SLC chassis. The rest of the modules are digital I/O, all local.
As happens to all bad quotes, this became an order last week. Now I must put it all together. Getting the PLC to do what I want with the PanelView is not an issue at all. Also, I will not "see" any hardware for months, until the whole project is approved "for construction".
I have downloaded the MVI46-MCM data sheet and manual and plan on reading it in detail over the next several days. Here are my questions:
1) I do not need this module to "control" anything in my scope. It is simply for the customer's interface. Do I need to do anything more than configure the M1 file in the RS Logix 500 software? In other words, can I trust the vendor's sales brochure's claim of simplicity? Or is this an unexpected, painful, time-consuming task?
2) Do I need to map any bits into any special register for him to pick up over Modbus? Or is this the responsibility of the DCS programmer? After all, it's his interface. I just don't know who picks up where.
3) Are there any odd hardware restrictions or other anomalies of the MVI46-MCM of which I should be aware? For example, it looks like I can put this in any available single slot.
4) What questions should I be asking the customer, if any, so my design and implementation goes smoothly?
As I said above, I will find out a lot more after reading up on the Modbus module, so please don't tell me to read the manual.
I'm really looking for very general advice and things to watch out for from those of you who have actually used this Modbus module in the past. I have described the whole project in case you have any other communication suggestions or ways to do it better or cleaner. Since I'm just starting to sketch the design out and prepare my ACAD drawing package, now was a good time to seek suggestions for a better system.
REMEMBER: I know how to program the PLC and build PanelView screens. I know how to get these to "talk" to each other. Although not to sound ungrateful, please don't waste your time on making suggestions that don't apply to how Modbus affects the project's scope.
Lastly, money is no object on this control project. Percentage-wise, my controls are about 2-3% of the overall project's budget, so a thousand here or there is meaningless. And by the way, I'm controlling a process (conveyors and other simple on-off devices) at a power plant.
Thanks in advance for any productive replies!!!
I have a project to design that is similar to another one that I did a few years ago without any problems.
On the new project, I am proposing the PLC to be a SLC5/04 (catalog # 1747-L542). I am also using a PanelView 1000 color (catalog # 2711-K10C8). My old project was the same processor, except I used a smaller, monochrome PV550 (catalog # 2711-B5A8).
I'm not sure how far away these will be from each other yet. (I'm questioning the customer, but it shouldn't be more than 100' apart.) Last time I hooked these up via DH+ (blue hose) on CH0, the PLC was probably only 40-50 feet away from the PanelView. I'd like to do the same on the new project.
Now to the part in which I'm not completely sure... (DISCLAIMER: I know nothing about Modbus).
The project's specification wanted Modbus communication available to tie in to "the plant DCS" (distributed control system). To satisfy that specification at the quoting stage, I "googled" the topic, found a ProSoft InRax MVI46-MCM Modbus Communications Interface Module for SLC, and figured on throwing it in my SLC chassis. The rest of the modules are digital I/O, all local.
As happens to all bad quotes, this became an order last week. Now I must put it all together. Getting the PLC to do what I want with the PanelView is not an issue at all. Also, I will not "see" any hardware for months, until the whole project is approved "for construction".
I have downloaded the MVI46-MCM data sheet and manual and plan on reading it in detail over the next several days. Here are my questions:
1) I do not need this module to "control" anything in my scope. It is simply for the customer's interface. Do I need to do anything more than configure the M1 file in the RS Logix 500 software? In other words, can I trust the vendor's sales brochure's claim of simplicity? Or is this an unexpected, painful, time-consuming task?
2) Do I need to map any bits into any special register for him to pick up over Modbus? Or is this the responsibility of the DCS programmer? After all, it's his interface. I just don't know who picks up where.
3) Are there any odd hardware restrictions or other anomalies of the MVI46-MCM of which I should be aware? For example, it looks like I can put this in any available single slot.
4) What questions should I be asking the customer, if any, so my design and implementation goes smoothly?
As I said above, I will find out a lot more after reading up on the Modbus module, so please don't tell me to read the manual.
I'm really looking for very general advice and things to watch out for from those of you who have actually used this Modbus module in the past. I have described the whole project in case you have any other communication suggestions or ways to do it better or cleaner. Since I'm just starting to sketch the design out and prepare my ACAD drawing package, now was a good time to seek suggestions for a better system.
REMEMBER: I know how to program the PLC and build PanelView screens. I know how to get these to "talk" to each other. Although not to sound ungrateful, please don't waste your time on making suggestions that don't apply to how Modbus affects the project's scope.
Lastly, money is no object on this control project. Percentage-wise, my controls are about 2-3% of the overall project's budget, so a thousand here or there is meaningless. And by the way, I'm controlling a process (conveyors and other simple on-off devices) at a power plant.
Thanks in advance for any productive replies!!!