RBergmann
Member
I really did think that this was going to be easier than it has proved to be. Here's the challenge:
Using an IDEC ONC (open net controller, fancy name for this PLC) and the HSC (high speed counter) dedicated inputs, I want to convert the pulse train from a GF paddle wheel sensor to measure the flow rate of water in a pipe using 'K' factors to adjust the pulses to GPM for a particular size (and material) of pipe. I want to use "double words" (32-bit) in my math calculations but the IDEC has an odd way (to me) of using these double registers and I'm not sure that I've been manipulating them correctly. IDEC uses two 16-bit registers for double words (as you might expect) but the results are confusing. It looks like I need to convert the results in some fashion.
I primarily use Mitsubishi PLCs and the results of double word calculations are predictable and obvious. I often use 32-bit registers to manipulate decimal values to integers. So that I can display the results on an OIT and place a decimal where it belongs. Doesn't seem to work with IDEC's ONC (and 32-bit math is not available at all with the MicroSmart series, only multiplication supports 'double words'). What am I missing here?
Anyone familiar with IDECs? I thought that I was able to get past most of what I would consider to be limitations but the math does me in.
I want my basic approach to be to take the number of pulses over a period of time (say a minute) and divide this by the 'K' factor. My initial approach is to start the time base and the pulse count simultaneously, get my results and reset the count and timer. I now get values all over the map.
Watcha think?
... rab
Using an IDEC ONC (open net controller, fancy name for this PLC) and the HSC (high speed counter) dedicated inputs, I want to convert the pulse train from a GF paddle wheel sensor to measure the flow rate of water in a pipe using 'K' factors to adjust the pulses to GPM for a particular size (and material) of pipe. I want to use "double words" (32-bit) in my math calculations but the IDEC has an odd way (to me) of using these double registers and I'm not sure that I've been manipulating them correctly. IDEC uses two 16-bit registers for double words (as you might expect) but the results are confusing. It looks like I need to convert the results in some fashion.
I primarily use Mitsubishi PLCs and the results of double word calculations are predictable and obvious. I often use 32-bit registers to manipulate decimal values to integers. So that I can display the results on an OIT and place a decimal where it belongs. Doesn't seem to work with IDEC's ONC (and 32-bit math is not available at all with the MicroSmart series, only multiplication supports 'double words'). What am I missing here?
Anyone familiar with IDECs? I thought that I was able to get past most of what I would consider to be limitations but the math does me in.
I want my basic approach to be to take the number of pulses over a period of time (say a minute) and divide this by the 'K' factor. My initial approach is to start the time base and the pulse count simultaneously, get my results and reset the count and timer. I now get values all over the map.
Watcha think?
... rab
