PM8000 High Speed Metering

[Andy_Hubert]

I have a customer here who has some PM8000 meters, they would like to read the HS values from the modbus registers shown below.

In Demo mode these do not seem to update any faster than 1 second.

Has anyone tried this before? and do you get a much faster update of the registers.

Thanks

HS Current A

21000

2

FLOAT32

A

R/O

numeric

---

HS I a

CT_A

MEM

None

HS Current B

21002

2

FLOAT32

A

R/O

numeric

---

HS I b

CT_A

MEM

None

HS Current C

21004

2

FLOAT32

A

R/O

numeric

---

HS I c

CT_A

MEM

None

HS Current N

21006

2

FLOAT32

A

R/O

numeric

---

HS I 4

CT_A

MEM

None

HS Current G

21008

2

FLOAT32

A

R/O

numeric

---

HS I 5

CT_A

MEM

None

HS Current Avg

21010

2

FLOAT32

A

R/O

numeric

---

HS I avg

CT_A

MEM

None

HS Frequency

21016

2

FLOAT32

Hz

R/O

numeric

---

HS Freq

HZ

MEM

None

HS Voltage, A-B

21018

2

FLOAT32

V

R/O

numeric

---

HS Vll ab

PT_V

MEM

None

HS Voltage, B-C

21020

2

FLOAT32

V

R/O

numeric

---

HS Vll bc

PT_V

MEM

None

HS Voltage, C-A

21022

2

FLOAT32

V

R/O

numeric

---

HS Vll ca

PT_V

MEM

None

HS Voltage, L-L Average

21024

2

FLOAT32

V

R/O

numeric

---

HS Vll avg

PT_V

MEM

None

HS Voltage, A-N

21026

2

FLOAT32

V

R/O

numeric

---

HS Vln a

PT_V

MEM

None

HS Voltage, B-N

21028

2

FLOAT32

V

R/O

numeric

---

HS Vln b

PT_V

MEM

None

HS Voltage, C-N

21030

2

FLOAT32

V

R/O

numeric

---

HS Vln c

PT_V

MEM

None

HS Voltage, L-N Average

21034

2

FLOAT32

V

R/O

numeric

---

HS Vln avg

PT_V

MEM

None

[Anonymous user]

Since the are almost in order I guess it would be smart to create a Modbus Register Group that reads all signals at a time

I assumed it was SmartStruxure, but maybe it wasn´t

Christer

[patrickw · Accepted solution]

Hi Andrew,

You are correct that the HS Power Meter Module only updates once per second in demo mode.  With a non-demo volts mode, the data is refreshed every half-cycle. 

The caveat with reading this over modbus, is that the round-trip comm delay in making a request and getting a response for highspeed data is variable.  Depending on the meter loading it could take up to a second to get a response (metering and logging is always higher priority than comms).  You will need to benchmark it in your specific scenario to see if it will be fast enough for your needs.

[Andy_Hubert]

Hi Patrick,

Thanks for the reply, that is exactly as I had hoped.

My customer is redaing the registers from a PLC connected via TCP, so it should be fast enough.

Thanks

Andy