How to count pulses into DM?

[aassbeer 0]

Hello! I need to add "1" into a DM each time there is an input-pulse. This is supposed to function as a counter to show values on a numeric display (NT-21) Will use a "move" function block with "0" to reset it. The PLC is an Omron CJ. How can it be done?

[banker 2]

Hi Aassbeer You can use the instruction @+ Input ------[]--------------------@+DMxx &1 DMxx Banker

[aassbeer 0]

Heihei banker! That function will only add "1" once, right? I need to add it several times to raise the numeric value on my TS. Like this 1 puls = DMxx=1 (1) 2 pulses = DMxx=2 (1+1) 3 pulses = DMxx=3 (1+1+1) 4 pulses = DMxx=4 (1+1+1+1) and so on...

[banker 2]

Yes it will ad "1" every time the input goes high. Banker

[aassbeer 0]

Take this example: ------[puls]--------------------@+DM10 &1 DM20 1. DM10 is first set to "0" 2. There is a puls input, and DM20 will become "1". 3. The puls falls, DM20 looses "1" It does not hold it, so it cannot function as a counter. Do you agree?

[BITS N BYTES 66]

Increment Binary with a differentiation up will do the trick. For example the rising edge signal of YOUR INPUT will increment D100 by 1. | |-----------|YOUR INPUT|------------[@++D100] |

[banker 2]

HI No DM men. "looses". To use my code use the same DM like this @+ DM20 &1 DM20 and use the move inst. for reset. Try to test in the simulator. Banker

[Marco8037 0]

Hello: Use this code: Input pulse -----| |--------------@++ Dxx That's the intruction nr. 490 an is usel for a binary increment. (values , in decimal, from 0 to 65 535) Use The character "@" to count all the pulses. "@" means a differentiate up of the input. However, this is not the best way to count pulses, if the frequency is too hi. If the frequency input is too hi, by this way, your PLC will not count all the pulses. If you have a big frequency on the input, like an encoder, for example, there are a better way in the CJ1M to count the pulses. However it is only possible on the CJ1M CPU 21, CPU22 and CPU23. CPU 11; CPU12 and CPU 13 don't support that option. If you are using the CPU 21 or 22, or 23 I can tell you how to count the pulses in a frequency up to 100 kHz. let me know what CPU do you have and what do you have connected in the input. Do you have a sensor, an encoder,what kind of encoder? Encoder TTL, encoder push pull?

[aassbeer 0]

Hi! It's an CJ1G-H CPU45. The pulse is coming from a flow sensor and is no more than 10Hz. Will try the programming lines mentioned in the above post's today. Thank you all for spending your time! Edited 23 Jun 2009 by aassbeer

[aassbeer 0]

Ended up with: Input pulse --||--------------- ++(590) Works great!