PLC with Frequency Inverter

[the_risk_master]

how to control frequency inverter from plc

Dear sirs/madams,


I have a project using Omron CJ1M PLC and an HMI with no problem (I have made the programs and user interface done) but my client required me to have an Inverter (PWM frequency inverter) 3G3JX so we can control the speed of the conveyor. Now my trouble is where to interface the frequency inverter in the PLC, i have spare DI's and AI's (no problem with that)... I just need some block diagram may be, where I can connect or cascade the inverter..



regards and many thanks,
the_risk_master

 

[mrcube_ns]

plc inverter

I'm Siemens PLC programer for more than 6 years. Configuration depends of customer needs, and what I/O has frequecy converter (FC).

My usual configuration is:
DI1: FC_working
DI2: FC_error
DI3: Automatic_mode
DI4: Manual_mode
DI5: Taster_START_FC
DI6: Taster_STOP_FC,
or DI5,6 can be replaced with one DI but you must use switch for start

DO1: Start_FC
DO2: Reset_fault_on FC

AI1: FC_frequency
AI2: FC_current

AO1: Speed_reference_for_FC

With this you have all information on PLC, and you can give all parameters to FC for work.


Second solution is to use communication for all parameters, start, stop etc.
Communication can be:
- Profibus,
- Fieldbus,
- Modbus,
or some FC own protocol

Best regards,


Mr.Cube

 

[Siniša]

modbus communication 3g3jx manual

You need either "dry" contact relay outputs or isolated NPN open collector output to control digital inputs of your drive. You select in programming of your drive what each input function is going to be. For analog control of speed you need either 0-10V or 4-20mA output from your PLC. (Later is recommended if there is long distance between PLC and drive)
If you read manual for PLC it should be obvious what you need to control the drive. Also make sure that any emrgency stop circuits stops drive directly without need for functional PLC.

 

[jentzsch]

Dear Mr. Cube,

I have a similar problem with the friend. It is as follows:
There is a asynchronous motor whose speed is already controlled by NORDAC500E frequency inverter. I would like to add this control to s7200 cpu 224.

Here are the connections of NORDAC500E:
obrazki.elektroda.pl/56_1288897474.jpg
I would kindly like to learn how could I communicate the FC with PLC. I would like to control the speed from PLC, later from a HMI maybe.

Thank you from now,

 

[SparkyBoy]

Inverters come with a standard I/O configuration for that make/model of inverter. If this does not meet your requirements you will need to study the installation and operating manuals to see if/how to change the standard config in the inverter software.

If continuous speed control is required then you will need an analogue output on your PLC and analogue input free on the inverter.

If stepped control will do then on most inverters you can define digital inputs on the inveter to act as speed up/speed down control or preset speed control.

Regards

Mark

 

[mrcube_ns]

Dear Mr. Cube,

I have a similar problem with the friend. It is as follows:
There is a asynchronous motor whose speed is already controlled by NORDAC500E frequency inverter. I would like to add this control to s7200 cpu 224.

Here are the connections of NORDAC500E:
obrazki.elektroda.pl/56_1288897474.jpg
I would kindly like to learn how could I communicate the FC with PLC. I would like to control the speed from PLC, later from a HMI maybe.

Thank you from now,

The most simple way to regulate (control) freq. converter is to do it via analog signals. (See attachment)

You must have analog output on your PLC (or add one if you don't have it).
If you connect 0-10V analog output, in PLC Code copy 0 to AQW0 and you'll get 0V, copy 32000 and you'll have 10V. Same is for current 0 - 0mA, 6400 - 4mA, 32000 - 20mA.

You have to select in frequency converter that speed reference is analog input. To put some jumpers to right position (See attachment - depends which signals you have)...

And that's it.

224 has only one communication port, so if you want to use it for HMI, than you cannot communicate with freq. converter. My advice is to use analog signals it's much simpler.

Best regards,

Mr.Cube

 

[lss_00]

Other method for controlling VDF(model depended) is by using 2 DO (increase-decrease speed) and 1 AI for speed feedback in order to obtain the desirable speed. This can be by proraminng two DI on the VDF.

 

[mei163]

Re: how to control frequency inverter from plc

Dear sirs/madams,


I have a project using Omron CJ1M PLC and an HMI with no problem (I have made the programs and user interface done) but my client required me to have an Inverter (PWM frequency inverter) 3G3JX so we can control the speed of the conveyor. Now my trouble is where to interface the frequency inverter in the PLC, i have spare DI's and AI's (no problem with that)... I just need some block diagram may be, where I can connect or cascade the inverter..



regards and many thanks,
the_risk_master

I think it's simple. What you need to do is just refer to the manual of the inverter. The block diagram will be clear in the manual.

 

[juven]

link about conveyor application with plc : Conveyor Control Using PLC

 

[rcrescini]

We have 2 units of EATON AF AC Drives (Model AF-1500). Both have the same parameter setting, but when we run it, the other just run until 10Hz only, the other one is 60Hz. We have already reset the unit and re-entered the same setting, but still it runs only at 10Hz.

 

[MHOSNA2010]

Re: how to control frequency inverter from plc

first read the manual book of Inverter . I think it would be a very simple solution if you use an analog output module ( 0-10 V DC) and connect it to inverter control terminal where potentiometer is connected. Don't worry regarding 3 wire connection , you will connect +10V point in Signal terminal and -ve to Common point. I hope you will get the result.

---------- Post added at 13:40 ---------- Previous post was at 13:36 ----------

please check the reference signal for speed. is it 0-10 VDC or 4-20mA DC ? Connection of reference signal is ok ? Check the Drive individually by giving the individual reference signal.