groov RIO edge EMU


The GRV-R7-I1VAPM-3 is a groov RIO energy monitoring unit (EMU) designed as an intelligent, distributed power and energy monitoring module. With built-in web-based configuration, commissioning, and flow logic software—plus support for multiple OT and IT protocols—the groov RIO EMU offers the flexibility to fit into either IIoT projects, especially those that require energy data acquisition or communications, or traditional energy management control systems

The groov RIO EMU simultaneously measures volts AC RMS and amps AC RMS on Category III wye (up to 400 VAC) or delta (up to 600 VAC) circuits. It can monitor three-phase AC current using 0.333 V, 1 V, or 5 A current transformers (CT). Each phase can be configured to ignore signals below a specified threshold in power measurement and energy accumulation to help you tune signal accuracy.

From the two measured field inputs, the module automatically calculates a total of 64 data values, including voltage and current; true, reactive and apparent power; power factor, frequency, net energy, and other values, as well as accumulated energy values for all phases.

You can use groov RIO EMUs in two ways:

  • As an edge energy monitoring unit, communicating data between loads and data destinations. You can:
    • Push data directly to on-premises or cloud apps, databases, or other software, typically using the included Node-RED
    • Publish data to an MQTT broker
    • Respond to Modbus/TCP requests for data
    • Configure with browser-based groov Manage software
    • Manage local user accounts and permissions, or from a central location through an LDAP server
  • As a traditional energy monitoring unit, configuring channels through your control program:
    • With a groov EPIC processor running a PAC Control strategy; add a groov RIO EMU as an I/O unit
    • With CODESYS applications, download and install the Opto 22 CODESYS Library Package to the CODESYS Development System, then add a groov RIO EMU as an Ethernet device
    • With a custom control program through either groov RIO’s OptoMMP memory map, its REST API, or through secure shell access (requires free GROOV-LIC-SHELL license)

The GRV-R7-I1VAPM-3 has a communications processor with two switched Gigabit Ethernet interfaces, one capable of Power over Ethernet (802.3af PoE Class 0) connections, supplying power to the groov RIO. It also has:

  • Supply terminals to connect to a 10-32 V DC power supply.
  • A USB host port, which can be used to connect additional devices like a Wi-Fi adapter, a USB memory stick, or a USB-to-serial adapter (none included).
  • Status LEDs to display the status of power, network, and electrical activity.
  • One 13-pin removable field I/O termination connector with spring clamp wire retention.
Specification GRV-R7-I1VAPM-3
Maximum UL61010-3 Measurement Category Category III 600 VAC
Delta Voltage Input Ranges, Vrms 600, 520, 260
Wye Voltage Input Ranges, Vrms 400, 300, 150
Voltage Accuracy
(% of range @ 50—60 Hz, excluding Voltage transformer)
Wye: ±0.35%, Delta: ±0.5%
Current Transformer (CT) Outputs Supported 5.0 A, 1.0 VAC or 0.3333 VAC
Current Accuracy
(% of CT range @ 50—60 Hz, excluding Current transformer)
Power Accuracy
(% of (Vrms range) * (CT current rating), @ 50-60Hz)
Data Refresh Time 1 s
Step Response Time 1 s
Problem Indication Vrms out of range, Irms out of range
Number of Data Channels 64
Ethernet Two switched Gigabit ports; daisy-chainable; ETH1 with 802.3af PoE powered device (PD)
USB One Port, USB 2.0 HS
Memory 1 GB RAM, 4.0 GB user space
Power Supply 802.3af PoE Class 0 or 10—32 V DC (but not both)
Power Consumption 4.5 W
Isolation (field to Ethernet / power input) 3600 VAC working, 5400 VAC transient
Isolation (channel-to-channel) N/A
Minimum GRV-R7 Firmware Version 3.3.0
Minimum groov EPIC Firmware Version 3.3.0
Minimum PAC Project Version 10.4000
Minimum Library Package for CODESYS Version
Field Connector Wire Size 28—14 AWG
Torque, field connector screw 2.5 in-lb (0.28 N-m)
Power Connector Wire Size 22—14 AWG
Torque, DC power connector screws 7.0 in-lb (0.79 N-m)
Torque, panel mount tab screw 2.0 in-lb (0.23 N-m)
Temperature (operating) -20 °C to +70 °C
Temperature (storage) -40 °C to +85 °C
Relative Humidity (non-condensing) 5—95%
MTBF (minimum, 25 °C) 1.2 Mhrs
Agency Approvals UL/cUL(Class 1 Div. 2); CE, ATEX(Category 3, Zone 2), RoHS; DFARS; CB Scheme; UKCA
Warranty 30 months