ITM3 option board

On 03 May 2012, Elster Solutions announced the end-of-life for the ITM3 option board. Active marketing and sale of the product has ceased.


Elster's internal telephone modem (ITM3) provides modem communication capabilities to the ALPHA Plus and A3 ALPHA meters. The ITM3 has outage reporting capabilities, intrusion detection, off-hook detection, and line sharing capabilities. For the A3 ALPHA meter, the ITM3 also supports dual report port access and 1 MB extended memory installed directly on the option board.


The ITM3 option board can support various option boards on both the ALPHA Plus and A3 ALPHA meters. With an option board installed, the ITM3 can support 2, 4, or 6 relays.


The ITM3 option board is compatible with wide voltage range ALPHA Plus meters Release 2.7 or later. A3 ALPHA meters require Release 3.0 or later to support the ITM3.

Outage reporting Intrusion & off-hook detection Line sharing Dual remote access Extended memory  
Data sheet  

When equipped with an optional outage reporting battery, the ITM3 option board can report power outages that meet user-specified criteria. ALPHA Plus meter outage reporting calls are made using the Elster Electricity protocol; A3 ALPHA meter outage reporting calls are made using ANSI C12.21 and C12.19.

Intrusion detection. When another telephone extension sharing the same line is attempting a call while the modem is off-hook, the modem ceases communication and immediately disconnects allowing the other extension to use the line. The modem will then follow the user-configured retry strategy to retry the call later.

Off-hook detection. When the telephone line is in use before the modem attempts a call, the modem will follow the user-configured retry strategy to retry the call later.

By using the ITM3 in conjunction with the RS-485 option board on a single meter, up to 31 meters (each with an RS-485 option board only) may share the same telephone line without the need for external equipment to install or maintain. All meters can be read making a single telephone call.

On the A3 ALPHA meter only, the ITM3 may be used to enable dual, simultaneous remote port access to the meter. To enable, simpy install the ITM3 along with a second communication option board (RS-232 or RS-485). This provides an economic solution when a second party desires direct access to the meter (for example, end customer access, power grid management, etc.)

When used on an A3 ALPHA meter, the ITM3 option board may be optionally provided with 1 MB of extended memory for additional interval data recording. The memory, when requested at the time of ordering, is provided directly on the ITM3 circuit board.

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