The Index AMI HW3 connects to each meter via a compatible point-to-point harness: an A+/B−/GND pair between the Index AMI's phoenix connector and the meter's RS485 or RS232 terminal block. This guide documents the wiring and reference images for the compatible harnesses.
Master compatibility table
| Ref | Meter | Port | Protocol | Harness |
|---|---|---|---|---|
| AMI-01 | Microstar P2000-D / D2000 | RJ45_2 | RS485 | Validado |
| AMI-02 | Microstar P2000-D | RJ45_2 | RS232 | Validado |
| AMI-03 | Microstar P2000-D | RJ45_1 | RS232 | Validado |
| AMI-04 | ISKRA MT174 | — | RS485 (DLMS/COSEM) | Validado |
| AMI-05 | Star DTS27 | RJ12 | RS485 | Validado |
| AMI-06 | Landis+Gyr ZMG405 | RJ12 | RS232 | Validado |
| AMI-08 | Elster A1800 | DB9 | RS232 | Validado |
| AMI-09 | ITRON SL7000 | RJ45-1 | RS232 | Validado |
✓ Validated means Noatec tested and certified that wiring with the Index AMI HW3.
Microstar P2000-D / D2000
Family of three-phase industrial meters widely deployed in Colombian utilities. The P2000-D and D2000 share the same RJ45 connector with two physical ports. A single meter can be read via RS485 (recommended for distances greater than 50 m) or RS232 (short range), and the operator can choose either of the two physical RJ45 ports.
AMI-01 — Microstar RS485 (RJ45_2)
Recommended harness for new integrations. RS485 provides immunity to electrical noise typical of industrial panels and reach of up to 1.2 km with category 5e cable.
AMI-02 — Microstar RS232 (RJ45_2)
RS232 variant on the same physical port as AMI-01. Useful when the meter is already configured for RS232 and you don't want to reprogram it.
AMI-03 — Microstar RS232 (RJ45_1)
RS232 variant on the alternative RJ45_1 port. Used when RJ45_2 is already occupied by another peripheral (optical reader, legacy modem).
ISKRA MT174
Three-phase meter from ISKRA (Slovenia) with native RS485 interface speaking DLMS/COSEM over IEC 62056. ONAC-approved and massively deployed in Colombian utilities. The family includes MT171/ME171 models (older, same interface) which are also compatible with this same harness.
AMI-04 — ISKRA MT174 RS485
External power required: the ISKRA MT174 cannot be powered from the meter bus. It requires an external 5–15 V source connected to the gateway. Do not connect the VCC pin of the communication connector — the animation explicitly shows this restriction.
Default DLMS/COSEM parameters
| Parameter | Value |
|---|---|
| Serial speed | 9600 bps (typical) — up to 38400 bps |
| Data bits / parity / stop | 8 / N / 1 |
| DLMS address (Client SAP) | 16 (Public Client) |
| Authentication mechanism | Low Level Security (LLS) |
| OBIS active energy total | 1.0.1.8.0.255 |
The OBIS code (Object Identification System) uniquely identifies each meter magnitude with 6 dot-separated numbers — for example 1.0.1.8.0.255 is total imported active energy. For the complete DLMS/COSEM protocol and object model detail, see the linked article at the end.
Star DTS27
Three-phase meter from Star (China) with a 6-contact RJ12 port. Speaks a Modbus RTU dialect over RS485 at 9600 bps. It is one of the most affordable meters in the AMI market and is used in rural cooperative projects and unregulated markets.
AMI-05 — Star DTS27 RS485
The harness includes a 300 mm RJ12 patch cord connecting the gateway's phoenix connector to the meter's RJ12. Note that it is Modbus RTU, not DLMS — energy registers are in holding registers 0x4000 (total active energy) and following.
Landis+Gyr ZMG405
Industrial three-phase meter from Landis+Gyr (Switzerland). Supports DLMS over RS232 via the optical port and over RS485 with an expansion module. This validation covers only the native RS232 port (RJ12).
AMI-06 — Landis+Gyr ZMG405 RS232 (RJ12)
RS232 is point-to-point: one meter per gateway. If your installation requires multiple Landis+Gyr meters on a bus, use the E350 / E650 family with an RS485 module and request a custom harness.
Elster A1800
Three-phase Elster meter with RS232 interface over a DB9 connector. Speaks DLMS/COSEM over IEC 62056 and is common in European and Latin American utility distribution networks. The AMI-08 harness is a 30 cm cable with a female DB9 connector at the meter end and a phoenix connector at the gateway end. 3 wires: TX (green), RX (red), GND (black).
AMI-08 — Elster A1800 RS232 (DB9)
3 wires: TX → RX, RX → TX, GND → GND. 30 cm AWG 22 cable. Female DB9 connector on the meter (pin 3 = TX, pin 2 = RX, pin 5 = GND). DLMS/COSEM protocol — same configuration parameters as the ISKRA MT174 and ITRON SL7000.
ITRON SL7000
Three-phase meter from ITRON with native RS232 interface over an RJ45 connector. Speaks DLMS/COSEM over IEC 62056 and is widely deployed in utilities and retailers. The AMI-09 harness uses an RJ45 patch cord cut to 30 cm — one RJ45 connector is kept at the meter end while the other end is stripped 2.5 cm to connect to the gateway phoenix connector.
AMI-09 — ITRON SL7000 RS232 (RJ45-1)
3 wires: TX → RX, RX → TX, GND → GND. The RJ45 patch cord is cut to 30 cm with the RJ45 connector towards the meter. DLMS/COSEM protocol at 9600 bps — same parameters as the ISKRA MT174.
Meter not listed
If your meter is not in this table but exposes RS485 or RS232 with DLMS/COSEM or Modbus RTU, Noatec manufactures custom harnesses. Send the meter's technical datasheet (with the serial port pinout) to soporte@noatec.co.
Next steps
With the harness connected, the next step is to configure the protocol and reading parameters from the app. See the Index AMI configuration guide for detailed steps using the Android app or the desktop tool.