problem with micro 1100 requiring mod-bus, DH-485 and ethernet

[g.robert]

Hello all.

I seem to be stuck. I have two problems:

1. I have a micro 1100, a C-more 12" touchscreen, N-tron 4 port hub and eight Watlow SD temperature controllers. I had intended to connect the C-more to the 1100 via ethernet utilizing the comm port 1 ethernet connection of the 1100 to the N-tron hub to the C-more. That would have left the RS-232 on the 1100 to mod-bus (via a AIC+) to the eight Watlow temp controllers. I only need to write the temp set point to the Watlows then read back the actual temp.

The C-more does not support ethernet communication to the micro 1100. I assumed the added AIC+ would allow me to comm the C-more and the mod-bus to the temp controllers. I was wrong, it will only give me one or the other.

Is there anyway I can get these three communications into the 1100 which only has two comm ports? I'm afraid not which leaves me with buying a panelview plus and software both total around $5600.00 which would allow for the PV to connect to the hub then to the 1100 via ethernet. This would allow the second RS-232 port on the 1100 to provide modbus (via the AIC+) to the eight temp controllers.Any ideas?

2. My second issue is that I have been unable to establish the desired comm to the Watlow with my modbus using an "MSG" command (see attached). I am not getting any errors. The watlow indicates a communication is happening. I may have a setting wrong in the MSG set up box. I don't know. The N7:2 adress has a value of 90 entered. I had hoped that 90 would pop up in the set point display of the watlow temp controller. Any ideas?

 

[Tom Jenkins]

You have more problems than ou realize.

The ML-1100 and the C-More both support Modbus, so you are OK there. However, Modbus RTU is a master slave protocol. The C-more wants to be a master, and the ML-1100 will also want to be a master when the message blocks are running. You can't have two masters.

The answer is to use a DH-485 or DF1 to Modbus communications bridge from Prosoft. http://www.prosoft-technology.com/ They have some models that allow multiple Modus ports, some of which can be masters and some slaves if I recall correctly. You have the ML-1100 talk to the Prosoft and have it talk to the C-More and the Watlows.

 

[g.robert]

Thanks Tom. I may not have explained how I need these to work with what I now have. I never intended to comm between the 1100 and C-more with Mod-bus. Only the Watlows with modbus. I hoped to comm the 1100 to the C-more via ethernet but can't.

I have the 1100 connected ethernet via port 1 for comm to our LAN via the N-tron hub. This is OK.

I have the C-more connected to the ethernet for comm to our LAN via the N-tron hub. This is OK.

I have the C-more connected to the 1100 via port 0 as DH-485. I go from the RS-232 on the 1100 via cable 1761-CBL-AM00 to the AIC+ then to the C-more. This is OK.

I need a mod-bus communication to the eight watlow controllers. I have to loose the C-more connection at the AIC+, change the comm configuration on port 0 to Mod-bus RTU master to comm to the watlows. This I do not have working properly. I must solve this. In an ideal world I will also find a way to keep the C-more but time is an issue. Any ideas?

 

[cjh]

The MicroLogix 1200R may be a better solution. It has 2 comm. ports. One could be for the Cmore DF1 communications (use the 'fixed settings' comm. port and the other port could be your Modbus Master.

I've never actually tried this exact configuration before, so I would recommend running this by your local AB guy before trying it.

I have run 2 different DF1 devices off of the 2 ports though and it worked fine.

 

[g.robert]

Thanks but the 1100 has two comm ports and I need three communications now that the C-more won't comm to the 1100 via ethernet.

1. ethernet from 1100 to LAN
2. DH-485 from C-more to 1100
3. Mod-bus from watlows (8) to 1100

I only have two. I can swap the C-more to the PV plus and go ethernet. I'd like to avoid that. If I do do that, it frees up the second port conflict so it can now be dedicated to the Mod-bus to the watlow temp controllers. That being said, I am having trouble with my "MSG" set up to the watlows. I think it is in the modbus addressing.

 

[cjh]

Ah, Ok. So you need Ethernet from the 1100 back to another device (PC or something...) besides the HMI connection?

Then I would either follow Tom's suggestion or switch Cmore to PV+.

 

[DanYost]

If you want to keep your existing hardware, you could add a Data Station Plus. It can communicate to the Watlows via RS485 Modbus. I can also communicate to the 1100 via Ethernet or 232. It can also be a Modbus slave (232 or Ethernet), which the C-More can poll for the data from the other devices.

Regards,

 

[g.robert]

Thanks Dan.


This sounds promising. If I understand you correctly, I will:
1. Keep my ethernet comm from the 1100 comm port 1 to the N-tron hub then to my LAN.
2. Keep my ethernet comm from the C-more HMI to the N-tron hub then to my LAN.
3. Keep my DH-485 connection between the 1100 / AIC + and the C-more HMI.
4. Establish modbus comm from your product to the watlow temp controllers. Then from your product to the N-tron hub via ethernet. Then to my 1100 on the existing ethernet comm from the N-tron hub.

Is that what you are saying? If so, do I still use the MSG commands to send the read write signals from the 1100 to the watlows? I hope this can work.

 

[DanYost]

That is correct. Like we talked about on the phone, you will not need to add any code to your PLC.

Regards,

 

[g.robert]

Thanks Dan. I have ordered the part and will receive it Friday. Which software do I download from your site to set this up?

 

[kolyur]

Get Crimson from here:

http://www.redlion.net/Support/Downloads/SoftwareLibrary/Crimson2.html

 

[g.robert]

Thanks for the info. I spent hours on the phone with AB and Watlow. I got the solution here in 10 minutes.(that is no knock to AB or Watlow though)Thanks again.

 

[g.robert]

I know its the weekend but SOS

Hello Dan.



I established communication but I still have no read / write between the AB1100 and the eight Watlow SD temp controllers.



I spoke with Watlow and they seem to be unable or unwilling to help. Further complicating matters is the difference in terminologies being used. Watlow talks of LSW, etc and the Crimson setup talks word to long, etc.



I believe the problem lays with what value a place in my N registers and how the values need to be sent and received to the Watlows. If I want a set point of 100 degrees F to be placed in the Watlow controller placing 100 to the mod-bus address will not do that. The white pages I emailed you from Watlow are supposed to show what needs to be done. If you happen to get this email this weekend I would really appreciate help sorting this out. I am supposed to be done Monday morning. I understand if this matter will not be addressed over the weekend though.



Thanks in advance for any help.

 

[DanYost]

I knew you were in a hurry, so I decided to check in this morning.

The problem is that you are reading longs (32-bit values) from the Watlows, but you are writing to word (16-bit registers) in the Micro. You have 2 options.

Before doing this, I notice that you have your blocks reversed. According to your white paper, Registers 27 and 28 are the SP. From the info on page 3, these appear to be the 'on the wire' addresses. For the proper address in the DSP, you will want to add 1 to the starting value, so the Modbus registers in the Gateway Block should be 400028 instead of 27. I would say the same thing about the PV; the Modbus address should be 21 instead of 20.

1. Switch to using Ls in the PLC and adjust the Gateway Blocks in the DSP accordingly. This is the option I suggest, as it is the easiest to follow in Crimson 2 for trouble shooting purposes.

2. Continue using Ns (however you will need to convert them to/from a long at some point in the PLC) and change the gateway blocks to transfer the Modbus data. This will also require doubling your number of Ns on the PLC side, so it looks something like this:

Block 1
N009:0000 >> PLC1.400028
N009:0001 >> PLC1.400029
N009:0002 >> PLC2.400028
N009:0003 >> PLC2.400029
...

Block 2
N009:0020 << PLC1.400021
N009:0021 << PLC1.400022
N009:0022 << PLC2.400021
N009:0023 << PLC2.400022
...

As far as the 32-bit data transfer, you should be OK. The DSP treats the 'lower' Modbus register as the MSW, just like the Watlow does.


I will try to check in again this weekend, if I can't you can reach me on the phone after 8 am Eastern Monday.
Regards,

 

[g.robert]

Thanks very much for lookinng into this Dan. I would definitely like to go the easiest route. I have no idea what an "L" address is. I can find no information on that within RS 500 help files either. Am I missing something? Does my Micro 1100 have this type of address?


If I go with the coversion in option two, can anyone provide an example of how this is done within the micro 1100?

Lastly, will I be entering the actual number I want to see as the set point at the Watlow (100 in micro address = 100 degree F at Watlow)or something totally different to get the set point I want?

Thanks for your help and anyone else that may have first hand knowledge regarding this type of situation.