9 Communication
9.2 Modbus
158
SICAM MMU 7KG9663, Device Manual
E50417-H1040-C514-A3, Edition 01.2016
Use as Write Register
This data format enables up to 8 commands to be transmitted via the holding register for which the ON/OFF
bits are set to either 0/1 or to 1/0. If these bits are set to 0/0 or 1/1, no evaluation will be performed.
9.2.6.5
Data Type - Counter
General
With the
Counter
data type, units of energy are transmitted as counter pulses.
To calculate the primary value, the conversion factor 'Energy per counter pulse' is output as the Measured Val-
ue data type in addition to the counter pulses (see chapter 9.2.6.1). The primary value is calculated as follows:
Primary value = number of counter pulses * energy per counter pulse
The following information is sent to each counter using the Modbus protocol:
•
Counter pulses as 32-bit values (with sign)
•
Separate status indications for "invalid" and "overflow" for each counter
•
Energy per counter pulse in floating-point format for measured values (see chapter 9.2.7.13)
Counter Pulses
32-bit integers with sign allow a maximum of ±2 147 483 647 counter pulses before the counter overflows. The
Counter
data type is structured as follows:
Bit S (Sign)
Reserved for negative metered values
ON
Holding register 0141
OFF
Indication 8
ON OFF
Indication 7
ON OFF
Indication 1
ON OFF
Indication 2
ON OFF
Indication 3
ON OFF
Indication 4
ON OFF
Indication 5
ON OFF
Indication 6
Byte 3 (MSB)
Byte 2
Byte 1
S
Holding register 08xx
Byte 0 (LSB)
Counter (31 Bit)
...
...
Holding register 08xx+1
SICAM-MMU_7KG9663_US.book Page 158 Monday, December 7, 2015 12:22 PM