03-22-2012 07:33 AM
The key to making this work on Zetron RTU's is to create a seperate modbus driver for each set of holding registers you want to read. For instance in my application I needed to read the holding registers for counter #1 and counter #2. To do this I created one modbus driver object and labeled it MB_count1, then I created another modbus driver object and labeled it MB_count2. You will be using the same addresses and serial configurations for each object since they are the same RTU. I then had to put in expressions for counter #1 that would display addresses 42011, 42012, 42013, 42014,42015,42016 from MB-count1 and I inserted expressions for counter #2 that would display addresses 42021,42022,42023,42024,42025,42026. That is the only way you can get the controller to read the entire holding registers from the RTU's. This is a pain since you have to have seperate modbus drivers for each counter or accumulator register you want to read as well as having to utilize a seperate control panel window in lookout to display these even though you only need to use only part of the values that are read. Just to let you know, addresses 42011-42013 return the value of counter 1, addresses 42014-42016 return the period of counter 1, addresses 42021-42023 return the value of counter 2, and addresses 42024-42026 return the period of counter 2. If you have the zetron installation and operation manual Part #: 025-9209J for the Zetron 1708 and 1716 RTU, the charts for the addresses to the accumulators is on page 33 and the chart for addresses for the counters is on page 35. Hope this helps.
03-23-2012 06:17 AM
Yes that helps alot! The example in the Zetron manual only shows the script for the 'values', how did you write the script for the 'period' for a counter? I'm trying to read a pulse input from a flow meter on digital input 16 of a 1716 RTU (1 pulse for 10 gal).
Thanks for you help!
03-23-2012 11:58 AM
I didn't use the period since it is not resettable for the application I needed it for. I used a physical timer relay at the site so I had a time reference for my pulse. I was just using the pulse counter input and wrote my expression accordingly utilizing the time reference I set up with the timer relay that I installed. If you wanted to use the period, you probably will have to figure out what the timing is on it. I am not sure since I do not use it. I wish I could be more help.