9 Communication
9.2 Modbus
157
SICAM MMU 7KG9663, Device Manual
E50417-H1040-C514-A3, Edition 01.2016
9.2.6.3
Data Type - Indications (Read Only)
The
Indications
data type is represented by 2 bits in holding registers:
Where:
•
Q: status/quality bit: 0 = OK, 1 = invalid
•
V: Value bit: 0 = OFF, 1 = ON
Status or Quality Bit "Q"
An indication is invalid if the result of a calculation is based on an invalid measured value, for example the cal-
culated limit value of an invalid measured value.
If the indication is invalid, the quality bit is set to "1". The value
bit can be ignored in this case.
Example: The system frequency is invalid if the voltage is smaller than 15 % of the rated voltage when
measuring the frequency. Any limit-violation indication based on this value is also invalid.
For indications that are always valid, for example the internal device indication
Device OK
, "0" is transmitted
as the quality bit.
Value Bit "V"
The value bit indicates whether an indication is ON (=1) or OFF (=0).
9.2.6.4
Data Type - Controllable Indications (Read/Write)
The
Controllable Indications
data type is needed for:
•
The binary outputs of the SICAM MMU
•
Processing internal device commands (e.g. resetting the energy counters).
The holding register is used for read and write access in this context.
Use as Read Register
Where:
•
Q: status/quality bit: 0 = OK, 1 = invalid
•
V: Value bit: 0 = OFF, 1 = ON
See also chapter 9.2.6.3.
Q
e.g. Holding register 0101
V
Indication 8
Q
V
Indication 7
Q
V
Indication 1
Q
V
Indication 2
Q
V
Indication 3
Q
V
Indication 4
Q
V
Indication 5
Q
V
Indication 6
Q
Holding register 0141
V
Indication 8
Q
V
Indication 7
Q
V
Indication 1
Q
V
Indication 2
Q
V
Indication 3
Q
V
Indication 4
Q
V
Indication 5
Q
V
Indication 6
SICAM-MMU_7KG9663_US.book Page 157 Monday, December 7, 2015 12:22 PM