PAC4200 Read load data by Modbus FC 0x64

Transcription

1 PAC Load profile data Modbus TCP FC 0x64 Application Functionality for reading PAC4200 load profile data is already included in Powerconfig and Powermanager software. To process this data also by custom applications it is possible to read it directly from device by modbus function code 0x64. The following example is using the program SMTN Modbus/TCP Master Control which provides a programmable basic application for communication in Microsoft Visual Basic. Find more informations and download options online: Reading load profile data records Load profile memory is separated in 5 channels which contain the values for: Channel 1: Channel 2: Channel 3: Channel 4: Channel 5: Active power import Active power export Reactive power import Reactive power export Apparent power By the Data identifier (table 2), 6 different data sets can be selected which arrange the data (average, cumulated, extrema) and send it on request via ModBus. Each record contains a unique OID (Object ID) which allows addressing each record directly. The highest (newest) existing OID is always stored in the load profile counter at Modbus register 0x00E4. A request to OID 0x returns always the entry for the lowest (oldest) OID. If a non-existing OID (apart from 0) is requested, an error will return. To read the complete load profile memory following steps are required: 1. Request to OID 0x This will return the oldest load profile entry which contains the lowest OID. 2. Separate the lowest OID from entry. 3. Request the highest OID on register 0x00E4. 4. Start a loop from lowest to highest OID and request in each cycle the entry for the actual OID. Remark: In general it is also possible to get more than one entries with one request. Caused by the maximum length of 240 Bytes for a single Modbus request it is recommended to get only one entry by one request Finally convert the data respectively table 4. Page 1 / 6

2 Example for request structure: Table 1 Byte Bytes in Hex Description 1-7 Header 8 64 Modbus Function Code 9 00 Constant 0x Data Identifier (all channels with extrema) OID Number of records Description Table 2 - Data identifier (Byte 10) Description channels 1 to 5 (average and cumulated) with extrema channel 1 (average and cumulated) with extrema channel 2 (average and cumulated) with extrema channel 3 (average and cumulated) with extrema channel 4 (average and cumulated) with extrema channel 5 (average and cumulated) with extrema channels 1 to 5 (average and cumulated) with extrema and channels 1 to 5 (average) with extrema channel 1 (average) with extrema channel 2 (average) with extrema channel 3 (average) with extrema channel 4 (average) with extrema channel 5 (average) with extrema channels 1 to 5 (average) with extrema and channels 1 to 5 (cumulated) with extrema channel 1 (cumulated) with extrema channel 2 (cumulated) with extrema channel 3 (cumulated) with extrema channel 4 (cumulated) with extrema channel 5 (cumulated) with extrema channels 1 to 5 (cumulated) with extrema and channels 1 to 5 (average and cumulated) without extrema channel 1 (average and cumulated) without extrema channel 2 (average and cumulated) without extrema channel 3 (average and cumulated) without extrema channel 4 (average and cumulated) without extrema channel 5 (average and cumulated) without extrema channels 1 to 5 (average and cumulated) without extrema and channels 1 to 5 (average) without extrema channel 1 (average) without extrema Number 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x40 0x41 Page 2 / 6

3 Table 2 - Data identifier (Byte 10) Description channel 2 (average) without extrema channel 3 (average) without extrema channel 4 (average) without extrema channel 5 (average) without extrema channels 1 to 5 (average) without extrema and channels 1 to 5 (cumulated) without extrema channel 1 (cumulated) without extrema channel 2 (cumulated) without extrema channel 3 (cumulated) without extrema channel 4 (cumulated) without extrema channel 5 (cumulated) without extrema channels 1 to 5 (cumulated) without extrema and Number 0x42 0x43 0x44 0x45 0x46 0x50 0x51 0x52 0x53 0x54 0x55 0x56 Page 3 / 6

4 Example for requests using SMTN Modbus/TCP Master Control : It is not required so set the first 8 bytes manual because they are given by your entries in SMTN form. UnitID (= 1), Modbus funktioncode 0x64 (= 100 Dez) and count of additional bytes to transfer (= 7). Get entry with lowest OID Request: Table 3 Byte Bytes in Hex Description 1-8 Defined by entries in SMTN form 9 00 Constant Data Identifier (all channels with extrema) Request for entry with lowest OID Count of requested entries Page 4 / 6

5 Response: Table 4 Bytes in hex Description 01 Modbus address 64 Modbus user defined function code 68 payload length in bytes (starting with the following byte to the end, excluding CRC) 00 Constant 0x00 06 Data identifier OID of the load profile entry 01 Number of records inserted in this telegram (may be smaller than requested) 61 Length of record in bytes (including this byte).. 0x61 data bytes of record with OID 0x timestamp act.period 8 byte OID act. period (unique period entry identification index) average active power import act. period average active power export act. period average reactive power import act. period average reactive power export act. period average apparent power act. period cumulated active power import act. period cumulated active power export act. period cumulated reactive power import act. period cumulated reactive power export act. period cumulated apparent power act. period Max. value active power act. period min. value active power act. period Max. value reactive power act. period min. value reactive power act. period Max. value apparent power act. period min. value apparent power act. period real load profile period length act. period real load profile subinterval length act. period information flag bytes act. period powerfactor import powerfactor export Page 5 / 6

6 Get highest OID Highest OID is always stored in register 0x00E4 and can be read by Modbus FC 0x03. Depending to the used Modbus tool it could be necessary to change the register address with -1 or +1. In this example -1 is required and the request register is 0x00E3. Request: Response: Highest OID Get all entries: Now it is possible to address and read each entry between lowest (0x003045) and highest OID (0x00349D) in a loop. Page 6 / 6