Modbus/TCP in Poseidon2 and Damocles2 family

The Poseidon2 and Damocles2 works as a TCP Server at port 502 (Modbus standard). The Modbus/TCP communication takes place using the given addresses. For details, see http://www.modbus.org .

Caution: Modbus/TCP implementation support requires setting the " Slave ID " variable to number 2. Check the setting of this variable in case you are enable to establish a connection. (The actual name may differ in your software – it used to be an address to distinguish multiple devices on a RS-485 line in case of Modbus/RTU).

What you can find in this application note:

• We describe how to properly setup Modbus Poll program version 3.20
• You find out what is possible to read via Modbus/TCP protocol

Notice: Modbus Poll application version 3.20 in its unregistered version works only for 4 minutes after launch. It is necessary to restart the program after to run it again.

Mapping of variables for the Modbus/TCP protocol

Remote INPUTS

Remote OUTPUTS

Sensors

The Poseidon2 and Damocles2 works as a TCP Server at port 502 (Modbus standard). The Modbus/TCP communication takes place using the given addresses. For details, see http://www.modbus.org .

Caution: Modbus/TCP implementation support requires setting the " Slave ID " variable to number 2. Check the setting of this variable in case you are enable to establish a connection. (The actual name may differ in your software – it used to be an address to distinguish multiple devices on a RS-485 line in case of Modbus/RTU).

Program Modbus Poll & Damocles MINI

Dry contact inputs - model MINI

Connect the Damocles MINI unit to ethernet and power supply. Launch Modbus Poll application (mbpoll.exe file). In setup menu select option Poll Definition (keyboard short cut F2).

Picture a - Input setting

Setting of inputs in Modbus Poll program (Picture a)

• Slave ID: 2
• Function: definition of running function 02 INPUT STATUS for monitoring of input states
• Address: definition of used variables that will be loaded (for addresses see figure bellow). Beginning at the address 100 - ending at the address 103
• Length: length of loaded variables
• Scan Rate: delay between two following loadings
• Auto Read Enable: to enable automatic reading of values
• Click OK button to confirm

 

Picture b - Network parameters setting

Addresses of inputs in terms of protocol are configured, now set up connection to device itself.

• In Connection menu select Connect (keyboard short cut F3)
• Select TCP/IP
• Set up device IP address and Port (standard is 502)
• Push OK button to confirm

Application is now connected to selected device and in periodic interval loads input values (see the picture c).

 

Picture c - Values loading

Picture d - Damocles MINI - WWW page

>> Damocles MINI
Download and application of Modbus Poll + examples

 

Binary outputs (Damocles MINI)

Open Poll Definition menu to control binary outputs.

Picture e - Output setting

• Slave ID: 2
• Function: definition of running function 01 COIL STATUS for monitoring of output states
• Address: defines the address of used variables that will be logged (for addresses see figure bellow). It begins at the address 200 - ending at the address 201
• Length: number of loaded variables
• Scan Rate: delay between two loadings
• Auto Read Enable: to enable automatic reloading
• Click OK button to confirm

To control binary inputs select option 05 in function menu: Write Single Coil (short cut F7).

Picture f - Output control

You can safe setting of Poll Definition to mbp file to simplify your work. Any time you need it simply load the saved setting.

 

Modbus Poll & Poseidon2 4002

Temperature sensor - model4002

Open Poll Definition in menu.

• Slave ID: 2
• Function: definition of running function 04 INPUT REGISTER for monitoring of output states
• Address: defines address of used variables that will be loaded (for address see figure above).
  • Andrea 100 - number of sensors
  • Addressed 101 - current value
• Length: number of logged values
• Scan Rate: delay between two readings
• Auto Read Enable: to enable automatic reloading
• Click OK button to confirm

Picture ch - Setting of temperature sensor

Two lines are displayed. The first line shows number of connected sensors and the second current temperature with an accuracy of 0.1° C. Save your setting to mbp file to simplify work with Poll Definition. In case you need it, simply load saved setting.