The WattNode® Modbus® and WattNode Revenue Modbus meter is available with several factory options at an additional charge. See the WattNode Modbus manual (pdf) for more information and details about the registers mentioned below.
These options apply to the following two families of WattNode meters for the Modbus protocol:
- Option CT=xxx – Pre-assign xxx as the global CtAmps value.
- Except on Revenue models, this can be field configured or overridden using the CtAmps register.
- On WattNode Revenue models, Option CT will be factory-set to match the CTs specified when ordering the meter.
- Option CT=xxx/yyy/zzz – Pre-assign xxx to CtAmpsA, yyy to CtAmpsB, and zzz to CtAmpsC.
- Except on Revenue models, these can be field configured or overridden using the CtAmpsA, CtAmpsB, and CtAmpsC registers.
- Option FP – Adds fast update power registers with updates every 200 milliseconds to support utility feed-in limiting requirements for inverters.
- Option EP – Factory configure the Modbus RS-485 communications to default to even parity (E81)
- This can be field configured using the ParityMode register if you have meters that were ordered without this option and you need even parity. This can be overridden or turned off in the field by changing the the ParityMode register.
- Option 19K – Factory configure the RS-485 communications 19,200 baud.
- This can be changed in the field by switching the baud rate DIP switch, or by writing to the Baud register. If you write “0” to the BaudRate register, then the DIP switch setting will control the baud rate.
- Option 38K – Factory configure the RS-485 communications to 38,400 baud. Position 8 of the DIP switch will be ignored.
- This can be changed in the field by writing a new value to the BaudRate register. If you write “0” to the BaudRate register, then the DIP switch setting will control the baud rate.
- Option TCP-RTU – Configure the communications to the Modbus TCP-RTU protocol option for use with RS-485 to Ethernet converters (serial device adapters).
- This can be field configured or disabled with the ModbusMode register.
- Option AD – Factory configure the Modbus address.
- This can be changed in the field by by writing a new address to the Address register. If you write 0 (zero) to the Address register, then the DIP switch setting will specify the Modbus address.
Note: All WattNode Modbus meters can have their communication settings restored to factory shipped values by setting all DIP switch positions to “0” for ten seconds. If an communication option has been ordered, the meter will restore to include the settings from any options.
X Terminal Options
These options all utilize the X (auxiliary) terminal on the “MODBUS” connector:
- Option X5 – Provides 5 Vdc at up to 60 milliamps between the C (common) and X (5V) terminals.
- Option IO – Provides a digital input (level sensing and pulse counting) or output (for load shedding and other applications) on the X terminal.
- Option SSR – Provides a solid-state relay (contact closure) output between the X and C terminals for load shedding and other applications.
Contact the factory about the following special options:
- Option 232 – Provide RS-232 I/O in place of RS-485.
- Option TTL – Provide 5V TTL UART I/O in place of RS-485.