Landis+Gyr E650 Series User Manual page 73

Operation
Principle
dlms items
D000030110 d – E650 Series 3 (ZMD400AT/CT, ZFD400AT/CT) – User Manual
dlms can be compared to sending a letter: the sender writes the address of
the recipient on the letter and hands it to the post office for transport. The
way in which the postal department transports the letter is of no conse-
quence to the sender and receiver. The only important thing is that the
address of the recipient is clearly shown and that the letter is received, read
and it can be seen from whom the letter originates.
Units with dlms operate in a similar way. They provide the values – termed
objects – required by the receiver (e.g. control centre) and pass them via
interface to the transport medium (channel). How the values reach the re-
cipient is again immaterial for both parties.
dlms is an object-oriented language. The dlms objects

have an unmistakable name in the form of the EDIS identification
number

contain the value in an exactly defined form and

are configured in a similarly exactly defined format.
Objects of this kind are number of resets with date and time, cumulative
maxima, rolling mean values, maxima, energy statuses, associated stored
values, etc.
The sender feeds these objects to a transport medium, e.g. the telephone
network. This transmits them to the receiver, so that the objects are re-
ceived in the same form as supplied by the sender.
73/93
© Landis+Gyr AG