7–12
PQM POWER QUALITY METER – INSTRUCTION MANUAL
MODBUS FUNCTIONS
CHAPTER 7: MODBUS COMMUNICATIONS
7.2.8
Function Code
16 – Store
Multiple
Setpoints
Modbus Implementation
: Preset Multiple Registers
PQM Implementation
: Store Multiple Setpoints
This function code allows multiple Setpoints to be stored into the PQM memory. Modbus
"registers" are 16 bit (two byte) values transmitted high order byte first. Thus all PQM
setpoints are sent as two bytes. The maximum number of Setpoints that can be stored in
one transmission is dependent on the slave device. Modbus allows up to a maximum of 60
holding registers to be stored. The PQM allows 60 registers to be stored in one
transmission. The PQM response to this function code is to echo the slave address, function
code, starting address, the number of Setpoints stored, and the CRC.
MESSAGE FORMAT AND EXAMPLE:
Request slave 17 to store the value 01F4 to Setpoint address 1028 and the value 2710 to
setpoint address 1029. After the transmission in this example is complete, PQM slave 17
will have the following Setpoints information stored:
AddressData
102801F4
10292710
Table 7–7: Master/Slave Packet Format for Function Code 10h
MASTER
TRANSMISSION
BYTES
EXAMPLE
DESCRIPTION
SLAVE ADDRESS
1
11
message for slave 17
FUNCTION CODE
1
10
store setpoints
DATA STARTING
ADDRESS
2
10 28
setpoint address 1028
NUMBER OF
SETPOINTS
2
00 02
2 setpoints = 4 bytes total
BYTE COUNT
1
04
4 bytes of data
DATA 1
2
01 F4
data for setpoint address
1028
DATA 2
2
27 10
data for setpoint address
1029
CRC
2
33 23
CRC error code
SLAVE RESPONSE
BYTES
EXAMPLE
DESCRIPTION
SLAVE ADDRESS
1
11
message from slave 17
FUNCTION CODE
1
10
store setpoints
DATA STARTING
ADDRESS
2
10 28
setpoint address 1028
NUMBER OF
SETPOINTS
2
00 02
2 setpoints
CRC
2
C7 90
CRC error code
Содержание Multilin PQM
Страница 3: ...Courtesy of NationalSwitchgear com ...
Страница 4: ...Courtesy of NationalSwitchgear com ...
Страница 10: ...TOC VI PQM POWER QUALITY METER INSTRUCTION MANUAL TABLE OF CONTENTS Courtesy of NationalSwitchgear com ...
Страница 348: ...I 10 PQM POWER QUALITY METER INSTRUCTION MANUAL INDEX Courtesy of NationalSwitchgear com ...