PM1000H Current Reading Mismatch

[ciklee]

Hello,

We have a digital power meter EasyLogic PM1000H that we're trying to read the average voltage and current readings via Modbus RTU. However, we're getting mismatched current readings e.g. the LCD shows current readings of ~300A but the Modbus read shows ~1A. The voltage readings are good though e.g. both show ~245V.

Does anyone know what could be the problem? The Modbus register address that we read the average current from is 3010.

Thanks. 

[Charles_Murison]

Hello @ciklee ,

I am not PM1000 series expert so understand what I say could be wrong. The PM1000 series user guide suggests that only the PM1200 meter supports modbus https://www.se.com/ca/en/download/document/NHA1696401/ (page 13). It could be there have been changes made since this guide, new products or you have PM1200 meter. 

Using the above guide as reference I would question what registers you are using. Below is for individual readings.

The below set of registers need to be read as a block, all 20 registers at the same time.

Do you have examples of the raw data compared to what you except? Ideally per register rather than having registers grouped. 

Regards,

Charles

[ciklee]

Hi @Charles_Murison,

Our actual DPM model is PM1125H, which belongs to the EasyLogic PM1000H series (see photo below). Attached are the datasheet and Modbus register list in Excel file for this model.

 

The average voltage and current register addresses are 3036 and 3010, respectively according to the Excel file (screenshot below). Example raw data we're getting when reading these registers are 1131580239 for voltage and 1064509323 for current. When converted using IEEE754 calculator (e.g. https://www.omnicalculator.com/other/floating-point), the floating point values are 242.54V for voltage and 0.95A for current. The voltage reading is similar to those shown on the LED display of the DPM, but the current value is way off. The current shown on the LED display is in the range of 300++A (see screenshot above) but the value read from Modbus register is only ~1A.

Appreciate any help. Thanks.

[KPS]

Hello @Charles_Murison 

PM1000H (Hexa) series does have Modbus connection:

https://www.se.com/in/en/download/document/PLSED310089EN_Web/

and the Modbus register for current does match:

https://www.se.com/in/en/faqs/FA333460/

[Charles_Murison]

Hello @cikleeand @KPS  ,

Thank you for the links. I am not PM1000 series expert so I did not know about these links. Are you able to give the values for registers 3000 -> 3012, with each register on it's own? Yes 3011 and 3012 are not currents but request is intentional.

For example
3000: XXXX

3001: YYYY
....
3012: ZZZZ 

Just as a note, I was not able to see your images in previous post.

Regards,

Charles

[Robert_Lee · Accepted solution]

If you have access to ION Setup, you can use the Modbus Tester UI (highlight the meter, go to Tools -> Diagnostics and click on the Troubleshooting tab).  From the drop list, you can select Read Holding Register (0x03) enter the register address (3000) and the number of registers to read (12) and click Send.  Once data is returned, right click on any value and select Float 32B as the desired format.