Power Modbus (PwrModbus) Driver for Modbus Devices

Power Operation uses the Power Modbus (PwrModbus) driver to communicate to Modbus devices. Although Modnet is available to use, PwrModbus gives the user more flexibility and ease of use than Modnet.

NOTE: Modnet should still be used for some PLC Devices, such as the TSX Quantum and TSX Premium PLC ranges. There are two special Modnet Protocols that exist for these PLCs that will select the correct addressing modes, select certain INI values, and other settings to provide compatibility with these devices without the need to set any other special parameters.

Benefits of PwrModbus

These are the benefits of using PwrModbus for Modbus devices:

• Writing Real-Time tags – PwrModbus creates variable tags with different attributes that are specific to the device registers. Attributes such as register type, scaling, and priority, etc. can be added. Modnet cannot add attributes to the tag and manipulation has to be done after the value is read in.
• Logic Codes – Logic codes tell Power Operation how to mathematically operate on the values in device registers to give users the desired values. Logic codes include Date / Time, Scaled Registers Signed/Unsigned, Coil Register, and IEEE variations. Logic codes allow you to view the device register values without any manipulation to get the desired value. Logic codes allow you to use fewer tags to get the data. For example, to read an Energy (Consumption) tag with logic codes, you would need a single tag with the specific Mod10K logic code. In comparison, to read an Energy (Consumption) tag with the Modnet driver, you would need four tags (at minimum) to read each register, then you would need to perform the Mod10K algorithm on the registers (in Cicode), and finally read the result.
• On-board alarms – If a device has onboard alarms, the Power Modbus allows the creation of alarm tags that can retrieve the onboard alarms. This feature allows users to retrieve historical alarms if the device stops communicating to the Power Operation or for any other issue.
• Control Tags – Creation of tags that can do predefined controls on some standard devices for example Operate (ENERGIZE).
• Reset Tags – Standard device types include some pre-defined resets. These pre-defined commands cause proprietary functions within the device.
• Driver Parameters in Citect.ini – Numerous driver parameters available to fine-tune performance of the devices using the driver.
• Waveform – Supports download of waveforms on certain device types with waveform capabilities (Comtrade files).
• Advanced Logging Parameters – a debug logging system is implemented for the driver. Logging is integrated with the I/O server system log and it produces messages in order of appearance that is vital for troubleshooting issues with devices.