ModTool Communication with our Products

What is ModTool?

ModTool is our controlling/monitoring software tool offering features as communication statistics and packet analyzer. Thus, it mainly serves as diagnostic tool to verify connection and functionality. It can show you modbus packet structure and data sent, and help find the difference in data your system is sending/receiving.

*Note: All our interfaces uses Modbus - see this article for further details.

What can I use it for?

ModTool allows you to test Modbus communication with our interfaces, such as:

  • Test an interface with your PC (even without indoor unit)
  • Is the RS485 wiring correct?
  • Are the Modbus communication parameters correct?
  • Can I control and monitor the individual indoor unit parameters?
  • How do the Modbus command sequences exchanged between the Modbus master (ModTool) and the interface look like?
  • Control and monitor all indoor units on the same RS485 network, including groups of units wired to to the same interface. 
  • Examples: See sample Modbus frames.

Please note that reading communicated P1P2 data is not possible.

ModTool Download

ModTool software is attached to this article (scroll to end of this article).

Note: If you have installed our product RTD-LT/CA then download the ModTool version from this article: How to install the RTD-LT/CA .

 

ModTool Installation

USB to RS485 Adapter

The recommended RS485 to USB adaptor for use with ModTool is the FTDI USB-RS485-WE-1800-BT available from RS Components, RS Stock No. 687-7834.

ModTool Wiring

Wiring of the adaptor is as follows

Orange =DB/ Data+
Yellow = DA/Data-
Black = Gnd

All other cores should be cut-back and insulated.

ModTool as a Modbus Master

ModTool acts as a Modbus master. Therefore, please make sure that no other Modbus master is on the same Modbus network.

Note that our products may operate in specific mode in which one of the interfaces is a Modbus master. When operating in such a mode it is not possible to use ModTool to monitor or control the interfaces, unless a Modbus gateway is used (we recommend our interface RTD-DSX - click here for further information).

 

How to use

You only need to use the COM tab (in the Window-> Port Setup menu). Select the COM port to which the USB-RS485 adapter is connected (in the information box below 'Parity' you will read FTDI once you've confirmed selection).
*Note that ModTool acts as a Modbus master. Therefore, please make sure that no other Modbus master is on the same Modbus network.

Then click 'Open Port'

  1. Start ModTool and go to Window->Port Setup.
  2. Select the correct COM port to which the USB-RS485 adapter is connected (in the information box below 'Parity' you will read FTDI once you've confirmed selection).
  3. Set the Baud rate and Parity.
  4. Keep the Link Layer Method in default (Direct). There is no need to set an IP address. 
  5. In Window->Setup->Network the Modbus address search range is set. This address range is used for automatic searches.
  6. Click Open Port.
  7. In ModTool's GUI and when clicking on Lan a textbox on the lower left hand side appears which can be used to add an interface with a specific Modbus address. On the lower right hand side a tickbox is visible which if ticked initiates an interface search in the Modbus address range which has been set (see step 2 above).
    • The ADD button is for the case that you want to add a device with a known Modbus address to the Modbus network. So, instead of having ModTool scan through the whole address range you just add the newly connected device. ModTool will automatically recognize the device you have added, so you don't need to select the device you want to add.
  8. Once the interface is found its name and a number indicating its Modbus address appear.
  9. The GUI (Graphical User Interface) shows a tree structure on the left hand side and the controlling/monitoring parameters on the right hand side.
  10. Expand the device tree and select Control.
    • RTD-20 ERQ mode: 
      The Holding registers to control/monitor the RTD-20 in ERQ mode are H8001 through H8004 (see RTD-20 installation instructions). You will find these in the folder User Config\PA\ of the tree structure on the left hand side of the GUI.
  11. In the right window the parameters which can be set appear. By clicking on any of these with the left mouse button a textbox on the lower left hand side opens which allows selecting or setting a new value for the parameter.

Further data:

  • The unit's P1P2 address is the digit next to the unit's symbol.
  • Communication statistics:  Window->Comm Stats
  • View the parameter values in different formats: View->Format
  • Window->Comm Stats-> Raw Bytes the Modbus messages that are transferred to (red) the interface, as well as those received appear. By unticking the Log Comms Messages tickbox on the lower left the logging will stop.
  • Register addresses: Clicking with the right mouse-button on the parameter you're interested in (e.g. Setpoint) a window will pop up of which the last line indicates the register type (H..Holding register, I.. Input register) and address.
  • Various parameters can be controlled and monitored, e.g.
    • Setpoint, Mode, Louvre, Fanspeed etc.
    • Unit Readback data
    • Status of Inputs S1 to S6: Input registers 10001 to 10006. In ModTool these registers are in the folder Sensors where you can see S1 to S6.

ModTool Troubleshooting

If you're having issues with ModTool, please check the following points:

  • Use the recommended USB-to-RS485 adapter
  • Is there any other program using COM port? If yes, please turn it off.
  • Test with only one of our interfaces sitting on the RS485 network.
  • If you're running ModTool on Windows 10: Please try running ModTool in Windows compatibility mode (i.e. in Windows 7 mode).
  • There may be a compatibility issue between the USB-RS485 adapter and USB 3.0 ports. Please test the adapter on a USB 2.0 port.
    • An option would be to install an USB Hub (e.g. RS Stock No. 706-7117) with USB 2.0 ports between USB 3.0 port of laptop and adapter. It is an option we recommend testing. 
  • You may also want to try installing ModTool on a different laptop for comparison.
  • The USB-RS485 adapter driver may need to be updated in the Windows' Device Manager (Control Panel->Hardware and Sound-> Device Manager). Go to the FTDI website: http://www.ftdichip.com/Drivers/VCP.htm (for support on the FTDI driver go contact their support)
  • With regards to project-saving: Currently this option is not available.