PLC Testing TOOL

Hire a real PLC for testing your PLC program


We program diverse types of PLCs: different brands and models. Most of them are latest series from Allen Bradley, Schneider and Siemens. Applications are different too. Some applications have just tens of IOs with complicated logic which includes lots of PID loops. When others have a simple logic with hundreds of IOs. High number of IOs indicates that a high number of alarm rungs have to be developed. During the logic development you have to copy and paste lots of timers, similar looking rungs and, perhaps, UDTs/FBs (User Defined Data Types / Function Blocks). During the copying there is always a possibility to miss to change a timer's number to the next one. Or a latching bit is the same as in the previous rung. It happens a lot, with a graduate or highly experienced engineers.

There is only one way in assuring your PLC program is error free, it is a live testing of the developed PLC program. When you want to ship your work "polished" you have to have a PLC near your computer for the live testing. But it is not always available, due to either costs, diversity of the projects or remote work.

To be able to test PLC program anytime we have been using VPN to connect to our PLCs. We set a number of common PLCs in our workshop. Every PLC has its own ethernet connection to a specially configured VPN router.

We use it for logic testing of our PLC programs. We create a complex testing environment to provide high integrity and reliability of developed PLC programs.

We are offering you to hire a PLC via VPN from us so you can test your PLC logic.

Who IS this for

For both an experienced controls engineer or for a beginner.

If you are an experienced engineer and already have a PLC at your desk you can create a PLC network for serious communication tests. Or you can use Node-RED in combination with Siemens S7 communication node or Allen Bradley CIP comms node to create a complex testing environment to simulate field equipment connected to local IOs. Also some SCADA testing will require a few PLCs at the same time.

If you are a beginner you can practice your skills on the high grade PLCs without buying an expensive hardware. There are great PLC online courses where you can receive high quality theoretical lessons and practice it on our PLCs. See just a few links to the great PLC courses: Allen Bradley PLC Training - RSLogix 5000 Series (Shane Welcher's youtube channel) and RealPars on Siemens S7 (RealPars’s youtube channel).


You will have to create a VPN network between your PC and the PLC. It is a simple process, there are just 3 steps:

    • Download VPN Client
    • Send us a PLC booking request
    • Connect VPN Client to the PLC


Currently we have a number of Allen Bradley and Siemens PLCs set and ready to go. Some could be booked out by other users. We are bringing more brands and models of PLCs to our network.

We are trying to keep this table up to date. However, please contact us for either to confirm availability, enquiry on a specific PLCs or cost of usage.

PLC Model Availability

Siemens S7-1200    - Available
Siemens S7-1200    - Available
Siemens S7-1200    - Booked Out
Siemens LOGO!      - Available
CompactLogix 5332E - Available
ControlLogix 5561  - Available
ControlLogix 5574  - Booked Out
MicroLogix 1400    - Booked Out

Send email to to book your slot.


Q1: When trying to connect I'm getting an access error. Error Code 12: Access has been denied.

A1: This indicates that the VPN Client can connect to the server but the user has no permission to connect to this PLC hub. Possible reasons:

  • user’s time slot has expired or hasn’t started yet
  • trying connecting to wrong Virtual Hub Name

Solution: check the details (date, time and Virtual Hub Name) with confirmation email from us.

Q2: Do you provide a support on the PLC programming?

A2: We will help with establishing a connection to our PLCs. PLC programming consultation is out of free service, however we always can arrange a good deal.

Q3: How different is this from RS Emulator (or PLCSIM)?

A3: The emulator is a great tool, however it has a number of limitations: scan time is always slower (don’t know why), impossible to simulate communications between PLCs and there is no way to programmatically simulate IOs. The last one is a big one for us. With real PLCs via VPN we use Node-RED and Siemens S7 communication node or Allen Bradley CIP comms node to simulate field IOs. For example, to simulate an operation of limit switch at digital input 1 when a motor contactor is closed, we do the following: on output 1 it waits for 5 seconds and sending signal to input 1.


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