R
Ok, here goes.
I have a ventilation project for a car workshop, I am building new premises for myself and wanted a smart system. I ended up learning how to program a Siemens Logo PLC. It gives me the freedom to embed a few different functions to each other (ventilation, exhaust extraction, etc). My PLC is one with relay outputs, and now I have programmed it in a way that one relay output is used for each of four fan speeds I was planning to have.
That is:
no output active=fan stopped
Output 1 active=fan speed 1
Output 2 active=fan speed 2
Output 3 active=fan speed 3
Output 4 active=fan speed 4
Later I found out that one output might need to feed 2 logic inputs on the Altivar, I think this is done easiest by using diodes in the wiring between the PLC and the Altivar.
Now to the Altivar 12...M2. It has 4 logic inputs, and I initially thought I could just use one at a time to activate 4 different pre-programmed frequency outputs. All the basic configuration is there (electric motor specs), I was able to use it in local mode adjusting frequency output on the wheel.
Then it gets confusing to me. The user manual (5/2013) says 2- or 3-wire control. 2-wire control is sufficient if you want 4 different speeds but if one of those 4 speeds is 0 (motor stopped) I have only 3 running speeds left? Or, is it that one of the logic inputs needs to be a RUN command, and depending on the input states of these 2 control wires you could have 4 running speeds?
On page 69 of the user manual is a table showing I/O states for the different speed settings. One thing I don't understand at all is that there is no such thing as Preset speed 1, instead there is "reference". What is this?
Another thing that confuses me is that I have selected POS as for positive signal to mean a logic input is 1, but when I look at the input statuses in the maintenance view, it shows me each input is high when I use a jumper cable from each input to COM. Jumping +24V to the inputs doesn't do a thing. What of the wiring is necessary for my needs, is it enough to use the PLC relay outputs to connect the +24V to the logic inputs I need, or does it also need the jumper to LO- ? How about these AI1/+5V/COM, do I have to wire these even if I don't need them for any feedback or control? Messing with the setting I did configure it to 8 preset speeds, ending up in a situation I can't even start the motor in local mode anymore.. Jumping the logic inputs in remote mode doesn't do anything either..
I would really appreciate if someone could walk me through this, I have no clue of the correct setting and wiring.
Thank you very much in advance.
I have a ventilation project for a car workshop, I am building new premises for myself and wanted a smart system. I ended up learning how to program a Siemens Logo PLC. It gives me the freedom to embed a few different functions to each other (ventilation, exhaust extraction, etc). My PLC is one with relay outputs, and now I have programmed it in a way that one relay output is used for each of four fan speeds I was planning to have.
That is:
no output active=fan stopped
Output 1 active=fan speed 1
Output 2 active=fan speed 2
Output 3 active=fan speed 3
Output 4 active=fan speed 4
Later I found out that one output might need to feed 2 logic inputs on the Altivar, I think this is done easiest by using diodes in the wiring between the PLC and the Altivar.
Now to the Altivar 12...M2. It has 4 logic inputs, and I initially thought I could just use one at a time to activate 4 different pre-programmed frequency outputs. All the basic configuration is there (electric motor specs), I was able to use it in local mode adjusting frequency output on the wheel.
Then it gets confusing to me. The user manual (5/2013) says 2- or 3-wire control. 2-wire control is sufficient if you want 4 different speeds but if one of those 4 speeds is 0 (motor stopped) I have only 3 running speeds left? Or, is it that one of the logic inputs needs to be a RUN command, and depending on the input states of these 2 control wires you could have 4 running speeds?
On page 69 of the user manual is a table showing I/O states for the different speed settings. One thing I don't understand at all is that there is no such thing as Preset speed 1, instead there is "reference". What is this?
Another thing that confuses me is that I have selected POS as for positive signal to mean a logic input is 1, but when I look at the input statuses in the maintenance view, it shows me each input is high when I use a jumper cable from each input to COM. Jumping +24V to the inputs doesn't do a thing. What of the wiring is necessary for my needs, is it enough to use the PLC relay outputs to connect the +24V to the logic inputs I need, or does it also need the jumper to LO- ? How about these AI1/+5V/COM, do I have to wire these even if I don't need them for any feedback or control? Messing with the setting I did configure it to 8 preset speeds, ending up in a situation I can't even start the motor in local mode anymore.. Jumping the logic inputs in remote mode doesn't do anything either..
I would really appreciate if someone could walk me through this, I have no clue of the correct setting and wiring.
Thank you very much in advance.