MULTICAL® 62
TECHNICAL DESCRIPTION
Ka st up A/“ •
Technical
Des iptio •
5512-1036-GB_
D •
.2016
81
12
Data Communication
12.1
MULTICAL® 62 Data Protocol
Internal data communication in MULTICAL® 62 is based on the Kamstrup Meter Protocol (KMP) which both
provides a quick and flexible reading structure and fulfils future requirements to data reliability.
The KMP protocol is used in all Kamstrup consumption meters launched in 2006 and later. The protocol is
used for the optical eye and via plug pins for the base module. Thus, base modules with e.g. M-bus
interface use the KMP protocol internally and the M-bus protocol externally.
The KMP protocol has been designed to handle point to point communication in a master/slave system
(e.g. a bus system) and is used for data reading of Kamstrup consumption meters.
Software and parameter protection
The ete s soft a e is
implemented in a ROM and cannot be changed, neither deliberately nor by
mistake. The legal parameters cannot be changed via data communication without breaking the legal seal
a d sho t i uiti g the total p og a
i g lo k
.
Software conformity
Software checksum based on CRC16 is available via data communication and in the display.
Integrity and authenticity of data
All data parameters include type, measuring unit, scaling factor and CRC16 checksum. Every produced
meter includes a unique identification number.
Two different formats are used in the communication between master and slave. Either a data frame
format or an application acknowledgement format.
A request from master to slave is always sent in a data frame.
The response from the slave can either be sent in a data frame or as an application
acknowledgement.
The data frame is based on the OSI model using the physical layer, the data link layer and the
application layer.
Number of bytes in each
field
1
1
1
0-?
2
1
Field designation
Start byte
Destination
address
CID
Data
CRC
Stop byte
OSI
–
layer
Application layer
Data link layer
Physical layer
The protocol is based on half duplex serial asynchronous communication with setup: 8 data bits, no parity
and 2 stop bits. The data bit rate is 1200 or 2400 baud. CRC16 is used in both request and response.
Data is transferred byte for byte in a binary data format, of which the 8 data bits represent one byte of
data.
Byte Stuffing is used for extending the data value range.
