Created Date: April 01,2019

Created by: esp400

I'm trying to control a GS2 via analog speed reference. I'm scaling 0-60Hz to 4-20mA out of the Click Koyo to the analog input of the GS2. When I put a meter in series to check the amperage to see if it matches what the output status states is current mA level, I get nothing. When I put it on the 10VDC output of the drive (internally supplied) which is the terminal adjacent to the Analog Input on the drive, there's my current reference. So I believe I have a sinking output to a sinking input. How do I make this work? Any suggestions are greatly appreciated.

Created Date: April 02,2019

Created by: Tinker

One might alternatively consider adding a https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_series_plcs_(stackable_micro_brick)/analog_i-z-o/c0-04da-1 which not only has the more conventional sourcing output, it would also give you an additional three outputs in case you ever needed them.

On the other hand, an isolating conditioner would give you isolation, so if you only need one channel that might be the best option, but for more than one channel conditioners could get expensive.

Created Date: April 02,2019

Created by: Alexandru

Analog output is not defined in terms of sourcing or sinking. Only digital IO are defined in terms of sourcing and sinking.

Analog output is essentially a power supply able to provide the current. Two conductors leave the plc output: signal and com.

to connect the analog output to drive analog input:

1. Connect the drive analog com(AC) to the plc com port corresponding to the analog output

2. Connect the plc output to drive analog input(AI)

3. Make sure the drive is configured to accept analog reference (P4.00 set to 03)

This is off-topic, but I hope will be found useful:

About dc sinking or sourcing outputs

sourcing means that the load is already connected to negative rail of a dc circuit and the plc output provides a path from positive rail to the load. It is implemented using a bipolar pnp transistor as a switch.

Sinking means that the load is already connected to positive rail and the connection to the plc output provides a path to the negative rail. Is implemented using a bipolar npn transistor.

the load is a dc device like a dc relay.

about dc sinking or sourcing inputs

in this case, the load is represented by plc input.

the input is called sinking if the path provided by the device connected to the input is towards the negative rail.

It is called sourcing if it requires a path from positive dc rail.

Created Date: April 02,2019

Created by: Tinker

Analog output is not defined in terms of sourcing or sinking. Only digital IO are defined in terms of sourcing and sinking.

Analog output is essentially a power supply able to provide the current. Two conductors leave the plc output: signal and com.

The CLICK built in current outputs are weird, they are not power supplies, the are current sinks, and both outputs share a common so it is not clear how to put one in series with an external power supply, though now that I'm writing this, I'm wondering, if one was only using one analog output, could one connect the common to the load and the "output " to a suitable power supply?

Created Date: April 02,2019

Created by: esp400

to connect the analog output to drive analog input:

1. Connect the drive analog com(AC) to the plc com port corresponding to the analog output

2. Connect the plc output to drive analog input(AI)

3. Make sure the drive is configured to accept analog reference (P4.00 set to 03)

This is how it is connected. There is no current reference with this configuration.

Created Date: April 02,2019

Created by: esp400

I am using only one analog output from the PLC. That is really all I need so I'm thinking isolation is probably best. I 've never used a signal conditioner before or implemented one into an application. Is the one that is linked above gonna work with this application or should I just call in and have them spec it out? My coworker (controls engineer) also suggested perhaps buying the add on output module that would provide 4-20mA sourcing. Is this a better idea? Is there a way to use the 10VDC signal (internal power supply) out of the GS2 to accomplish this? I can see the current speed reference on the multimeter in the 20/200 mA range by interrupting the circuit and referencing the analog output of the PLC and the 10VDC signal out of the GS2.

Created Date: April 03,2019

Created by: Alexandru

You don’t need a signal conditioner or isolator. The purpose of such a device is to allow for example more receivers to be connected to the same analog signal supply. Therefore, the analog signal needs split and each circuit may need isolation to prevent interference. Not your case.

What you need is to understand the nature of the fault. You have a fault in your doing. Whether is your fault or a fault in hardware, is not clear now.

Let’s clear the hardware

1. Plc side

1.1. Connect a 3k resistor to analog out port. Connect an ammeter between the other end of the resistor and the analog com port.

( you could also use a voltmeter connected parallel with resistor, while resistor is connected between analog port and analog com)

1.2. Program the plc to output different analog values. Check the ammeter readings. If everything is fine, then the plc is clear.

2. Drive side

2.1. Configure the drive to accept speed reference from external potentiometer.

2.2. Connect a 3k potentiometer between AI+, AI and AC

2.3. Check on drive display the frequency change over frequency range. If everything is fine, the drive is clear.

I will risk an opinion, saying that you won’t clear the hardware. Main reason being an inconsistent configuration of the drive. Please reset the drive, reconfigure as required and if still doesn’t work, I would call support. It is possible that another drive parameter is not configured to allow motion with external analog reference.