[Modbus, blocking Write command]

4 hours ago, Fernando Castro said:

I mean, you are not wrong but after doing that, I don't see the point on using Modbus.

The main idea proposed by me is to use the standard SCADA Modbus protocol for connection.

That is, by making your own limited  Modbus protocol in the PLC, you can allow users to read or write something via SCADA without worrying about the possibility of messing up the settings.

In my case user can only set setpoint and read statistic via free  SCADA.

[Modbus, blocking Write command]

It is clear that the direct use of Slave Modbus mode does not have any protection against reading or writing to PLC memory.

I haven't tried to do something like password protection, but I think it's possible to run your own exchange Modbus commands using the Protocol FB when starting the PLC.

Here are the possible options:

- set the password that must be set (writed) by master (using an address that does not exist in the PLC and own "Simulated Modbus" protocol) and put the PLC in full access Slave mode via standard Modbus (and disable "Simulated Modbus" protocol until the next restart of the PLC or the programmed standard modbus write command action - reset the password);

- create your "Local simulated Modbus" with a set of available cells for writing or only reading via Protocol FB.

I was building "My Modbus"  to read a record of User defined Modbus codes in the range 65-72 (Not implemented in PLC). Everything worked without problems, so I think it's easy to create something like this to give write and read access to only specified cells using standard modbus codes or User defined Modbus codes.

[Data no retained on PLC when should]

Is it  CPU-for-Panel present?

Panel cannot operate independently. CPU-for-Panel must be plugged
into the back of a UniStream® HMI panel. The panel provides the CPU’s
power source. The CPU-for-Panel comprises:
1 IO/COM Bus connector for interfacing Uni-I/O™ & Uni-COM™ modules
2 Isolated RS485 and CANbus ports
3 Backup battery

[Reading Database from Siemens S7]

18 minutes ago, kpetro07 said:

trying to read from Siemens PLC

Model # or Siemens product code needed...

If Profibus on board 

https://www.moxa.com/en/spotlight/protocol-gateways/modbus-to-profinet-profibus/index

However, many user manuals and forums need to be studied in order to achieve what you want.

[V700 Modbus TCP communication with Exlar Servo]

One more tips. Is it in new installation the same power supply model used?

Some times wrong type power supply make problem for all installation.

[LewanSoul LDX-218 Servo]

4 hours ago, Des said:

Does that mean, if I use it say in the arm of my animatronic project, and there is any weight on the servo due to the arm being extended say, that when powered off the arm would drop down?

Yes, if no power - arm woud drop down.

In industrial applications, all motors have high-speed lockout brakes after tripping. The task of the brakes is to keep the robot in an arbitrary position after switching off.

The rotation of an arbitrary motor after power trip should be no more than one revolution. If this condition is not fulfilled, the robot says that it has lost the coordinate of the axis in which the brake is faulty.

Using servos like you suggest is a cheap solution but I haven't seen one with a brake. This is an increase in weight and additional wires and energy to control the actuator brake.

[V700 Modbus TCP communication with Exlar Servo]

I have observed communication problems in the V700 controller if the servo or frequency converters are not properly grounded.

Also, in this case, connecting the PLC negative power wire to machine ground helped.

I cannot predict all the reasons, but in such cases, I have observed that a slight change in the internal program (firmware) of the servo manufacturer can change the state of affairs for the worse. To test this hypothesis, it is necessary to go back to the previous versions of the servo drive from previous working installations.

[RGB LED control via a PLC]

https://muccosignal.com/product/surface-mounting-multicolor-rgb-warning-light/

You can use two PWM PLC output  for operate blue and red LED.  1-st start with 100.0% PWM duty on low temperature. Second with 0% on the same condition.

Both PWM  can be operated by Linearization FBs. Input temperature - outputs PWM setpoints. 

 

[Oh My, Who Would Have Thought.....]

8 hours ago, John_R said:

dark-seldom-explored-corners

8 hours ago, John_R said:

something-I-know-is-there-but-can't-find-it

8 hours ago, John_R said:

I-saved-because-I-know-someday-I-will-use-it

I specifically highlighted statements that are absolutely true.

 

8 hours ago, John_R said:

ebay (fun-money/beer-money is better than stuff I will never use)...

And it was because of such cases that I was able to get almost all type Vision PLCs  series for my laboratory (cave).

Therefore, the philosophical question is who will need them when I am going to retire.  

[V200-18-E4XB]

5 minutes ago, Ausman said:

They've done something seriously wrong to have upset the snap. 

Maybe they connect +24VDC power direct to analog input in current mode with 121.5 Ohm inpendance. +-40mA max possible on input. 

Approx 200mA appear if +24VDC direct connection present = "upset the snap".

[Modbus plc vision 130 data reading control and yaskawa inverter]

Hi, in your read command used only 1bit vector length.

Yaskawa operate with 16bit vector that must be transmitted to MI Vector.

[connect with EATON DC1]

communication-manual-for-variable-frequency-drives-variable-speed-starters-da1-dc1-de0-mn040018en.pdf

Please read p.12 for correct setup DC1. Connection parameter can not be changed. You must connect DI1 for operate drive via MODBUS.

Please use PC modbus software and Usb-RS485 converter for test connection before try to use Unistream PLC.

[V200-18-E4XB]

Plese check primary and secondary (power) module boards for damaged (burned) parts.

Resisor R1 on secondary board and R105-R117 on primary must be checked.

Then try to set jamper to 0-10V mode for all chanel and apply test voltage 1....9V to all analog  inputs . Result?

If voltage mode operate (you see readout) - you can use 500 Ohm resistor connected to analog voltage input and ACM for convert current 0..20mA to   0..10V

[V350 with IO-D16A3 output only reacts to initializing]

The elevator check routine is not called anywhere in the main program. Therefore, the output is not activated in any way... Which confirms the result on the elevator exit control window.

The author of the topic must put in the main program the Call Subroutine  (for 2 subroutine) from Utils menu .

[Ignition for Parts Track Trace]

Ignition.... What it is?

Maybe a translation error...

[V350 with IO-D16A3 output only reacts to initializing]

1. Please check subrouting call for used code.

2. Please Find O84 in code if any -(  )- coil used for it - S and -R Coil do not operate correctly.

3. Is it IO module connected to V350? It is not possible to simulate IO not connected to PLC.

4. You can go to Info Mode and try to operate  Outputs via Info Mode menu - Result?

 

[' To complete the download , a newer O/S version is required'']

Useful  information about OS

 

[V570-57-T20B-J Modbus Slave to US5-B10-T24 Master]

3 hours ago, Shahar said:

Question is it only for Unitronics frequency regulator or for all companies like Omron

Yes this UMI config only for Unitronics VFD.

You must program ladder code for operate Omron VFD.

[MI values are not saved and when the V560 starts with very high values. Visilogic.]

Is it MI3 present in this Data Table Read Row PARAMETER function ?

[MI values are not saved and when the V560 starts with very high values. Visilogic.]

Please try to Find MI3 in your program. You can see possible overwrite this MI in other part of program.

[Absolute encoder and oplc V350-35-T2]

In such conditions, the frequency of the signals arriving at the discrete inputs from the absolute encoder is approximately 5000Hz (1/1.2Hz=0.8s 4096/0.8s=5120Hz).

The operating frequency of discrete inputs is 100Hz (10ms Response time). Therefore, they will not have time to see rapid code changes in standard mode.

It will not be possible to use high-speed inputs because there are only 3 of them in this PLC.

The only way out is to try to quickly read standard inputs using interrupts in the PLC.

Read about it in the help and experiment with the absolute encoder if you have one available.

[V120, On-line connection with Ethernet to RS232 converter]

I think you need to test your RS232 port.

Please found terminal program and set  COM port.

Try to connect TX and RX pin in RS232 DB9 connector (pin2 connect to pin3).

Type any symbol in TX and send it to port - you must see the same symbol in RX menu. If you do not see sended symbol in RX display - your hardware-software configuration is not correct or Ethernet to RS232 adapter is damaged.

P.S. Is it this adapter correctly powered?

 

[V130 and EX90 physical connections, and dumping a project.]

Marking rungs with color even caused a scroll bug that was already fixed in version 94.

It is interesting that now there is no file with version changes on the Unitronics site.

This is probably to introduce information about the following new 96 version features.

[Can't share projects with same unilogic versions]

7 hours ago, Kestralcontrols said:

This is true for any project that has been modified using the laptop.

If a project has not been modified I can open it using the PC or laptop.

Don't know if this makes any difference, but PC is running windows 11 pro and laptop is running windows 11 home.

Please send message to support@unitronics.com

 

This topic is useful also

 

[PT100 Set up and how to Display on HMI]

8 minutes ago, bbcxo said:

No logic is needed to display the temperature reading on the HMI?

Yes. Only set Analog Input MI...  in Hardware Config and place number on screen with the same MI.