Phoenix Contact EEM-MA370-R

Compatibility

Compatible with EpiSensor Edge over Modbus TCP or Modbus RTU

The EEM-MA370-R is compatible with EpiSensor Edge over Modbus RTU, read through a ZMB-31 Modbus Interface or a Gateway serial port, and over Modbus TCP on its Ethernet port. Phoenix Contact documents the RS-485 terminals and factory serial settings, FC03 and FC04 reads, the 32-bit float word order and the process-data addresses used in this guide.

EEM-MA370-R, order number 2907980, using the EMpro online documentation English revision 004 (10 July 2026) as the starting map. Site check: read frequency first and compare it with the display before adding points. Read-only monitoring: no PIN, configuration, mapping-allocation or reset writes.

Connect it with

• Modbus Interface ZMB-3X From €399 ex VAT Configure
• Gateway ZGW-20 From €899 ex VAT Configure
• Evaluation Gateway on a Raspberry Pi Edge with one device licensed Free Set up

Models

Specifications

The RS-485 port has four terminals: GND for the shield, B- and A+ for the signal pair, and Ω for the built-in 120 Ω resistor, which is switched in by bridging Ω and A+. It leaves the factory at address 1, 9600 bit/s and even parity with one stop bit, and Modbus RTU is active by default.^3, 4

Exact model

EEM-MA370-R, order number 2907980¹

Voltage

Nominal 100 to 575 V AC phase-phase (57.7 to 333 V AC phase-neutral); measuring range 18 to 690 V AC phase-phase, 11 to 400 V AC phase-neutral; 45 to 65 Hz²

Current

External CT with 1 A or 5 A secondary and a primary from 1 A to 20,000 A; measuring range 0.05% to 120% of In²

Accuracy

Active energy class 0.5 S (IEC 62053-22); reactive energy class 2 (EN 62053-23); active power 0.5% to DIN EN 61557-12²

RS-485

Modbus RTU, 2.4 to 115.2 kbit/s; address 1 to 247 (default 1); default 9600 bit/s, even parity, 1 stop bit; terminals GND, B-, A+ and Ω^2, 3, 4

Ethernet

100Base-TX RJ45 (X1) with Modbus TCP, REST API and MQTT^1, 2

Supply

80 to 276 V AC or 120 to 300 V DC, under 4 W²

Housing and environment

90 × 80 × 64 mm DIN-rail housing; -25 to +70 °C operating; IP20 housing, IP40 display; up to 2,000 m; up to 95% humidity, non-condensing²

Interface

Documented measurements and integration boundaries for EEM-MA370-R.

• Addresses are the decimal register numbers Phoenix prints, sent as the zero-based PDU address: 32780 is 0x800C. Read with FC03; FC04 returns the same registers.
• Frequency at 32780 (0x800C): two registers, 32-bit IEEE 754 float, Hz.
• Total active power at 32790 (0x8016): two registers, 32-bit float.
• System current at 32825 (0x8039) and system conductor voltage at 32829 (0x803D): two registers each, 32-bit float.
• Word order: Phoenix calls it little-endian byte swap. The low word is in the first register, each word high byte first (CDAB on the wire): 123.456 (0x42F6E979) arrives as 0xE979 then 0x42F6.
• Optional mapped block: 125 read-only registers from 57600 (0xE100), filled through allocation registers from 57344 (0xE000) or the web server. Its content depends on that configuration.
• The complete register table, with units and dividers for every point, is in the product's download area under Application notes, and in the meter's web server register search.
• Keep writes out of the client: persistent changes need the PIN at 16403 and a 1 written to 16387, which a monitoring client should never send.

Setup

1. Confirm the exact article

   Read EEM-MA370-R and order number 2907980 from the front of the meter. Record the firmware version, serial number and the CT primary and secondary set in the meter.

2. Read the serial settings without changing them

   Check the Modbus address, baud rate, parity and stop bits on the display or in the web server. The factory settings are address 1, 9600 bit/s, even parity and 1 stop bit. Enter the same values in the Edge serial client or the ZMB-31.

3. Wire the RS-485 pair

   Connect A+ and B- to the twisted pair and GND to the shield. Bridge Ω and A+ only on the meter at the end of the line. Keep a single Modbus client on the line.

4. Read frequency first

   Send FC03 to 32780 (0x800C) for two registers and decode the float low word first, as in the worked read below. Compare the result with the frequency on the display.

5. Add the points you need

   Add system voltage, system current and total active power from the published addresses, then any further points from the full register table, checking each unit and divider. Keep FC06 and FC16 out of the polling configuration.

Common questions

Can Edge read the EEM-MA370-R over Modbus RTU?

Yes. Wire the RS-485 port to a ZMB-31 Modbus Interface or a Gateway serial port, match the serial settings and read with FC03. The same registers are also available over Modbus TCP on the Ethernet port.^3, 4, 5

What are the factory serial settings?

Address 1, 9600 bit/s, even parity and 1 stop bit, with Modbus RTU active. The address can be set from 1 to 247 and the speed up to 115,200 bit/s on the display, in the web server or over Modbus.^2, 3, 4

Where is the full EEM-MA370-R register table?

Phoenix Contact publishes it in the product's download area under Application notes, and the meter's web server has a register search once it is in service. This guide uses only the addresses Phoenix prints in its online documentation.^5, 6

Which word order do the float registers use?

Low word first, with each word high byte first. Phoenix calls this little-endian byte swap; many clients call it CDAB or word-swapped float.⁵

Can Edge read several values in one request?

Yes. The meter can copy up to 125 registers from different addresses into a read-only block starting at 57600 (0xE100). Set the allocation once in the web server, record it, then poll the block from Edge; keep the individual addresses for troubleshooting.⁶