Eaton IQ 150S, User & Installation Manual

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IM02601006E www.eaton.com D-2
IQ 250S D: DNP Map
In order to establish optimal communication with the IQ 250S meter, we recommend that you per-
form the Reset Link and Reset User functions. The Link Status is not mandatory, but can be per-
formed as well. The inter-character time-out for DNP is 1 second. If this amount of time, or more,
elapses between two consecutive characters within a FT3 frame, the frame will be dropped.
D.4: Application Layer
The IQ 250S meter’s DNP version supports the Read, Write, Direct Operate and Direct Operate
Unconfirmed functions.
• The Read function (code 01) provides a means for reading the critical measurement data from
the meter. This function should be posted to read object 60 variation 1, which will read all the
available Class 0 objects from the DNP register map. See the register map in Section C.6. In
order to retrieve all objects with their respective variations, the qualifier must be set to ALL
(0x06). See Section D.7 for an example showing a read Class 0 request data from the meter.
• The Write function (code 02) provides a means for clearing the Device restart bit in the Internal
Indicator register only. This is mapped to Object 80, point 0 with variation 1. When clearing the
restart device indicator use qualifier 0. Section D.7 shows the supported frames for this func-
tion.
• The Direct Operate function (code 05) is intended for resetting the energy counters and the
Demand counters (minimum and maximum energy registers). These actions are mapped to
Object 12, points 0 and 2, which act as control relays. The relays must be operated (On) in 0
msec and released (Off) in 1 msec only. Qualifiers 0x17 or x28 are supported for writing the
energy reset. Sample frames are shown in Section D.7.
• The Direct Operate Unconfirmed (or Unacknowledged) function (code 06) is intended for asking
the communication port to switch to Modbus RTU protocol from DNP. This switching acts as a
control relay mapped into Object 12, point 1 in the meter. The relay must be operated with qual-
ifier 0x17, code 3 count 0, with 0 milliseconds on and 1 millisecond off, only. After sending this
request the current communication port will accept Modbus RTU frames only. To make this port
go back to DNP protocol, the unit must be powered down and up. Section D.7 shows the con-
structed frame to perform DNP to Modbus RTU protocol change.