UM1530 Description
Doc ID 022957 Rev 1 7/26
The ST7570 embeds a full physical (PHY) and a medium access control (MAC) protocol
layer and services compliant with the open standard IEC 61334-5-1, mainly developed for
smart metering applications, but suitable also for other command and control applications
and remote load management.
A local port (UART) is available for communication with an external host, exporting all the
functions and services required to configure and control the device and its protocol stack.
The protocol layers and functions embedded in the ST7570 are:
Physical layer: implemented in the PHY processor and exporting all the primitive functions
listed in the international standard document IEC 61334-5-1, plus additional services for
configuration, alarm management, signal and noise amplitude estimation, phase detection
and statistical information.
MAC layer: implemented on the protocol controller and exporting all the primitive functions
listed in the international standard document IEC 61334-5-1, plus additional services for
configuration.
Management information base (MIB): an information database with all the data required
for proper configuration of the system (at both PHY and MAC layer).
Host interface: all the services of the PHY, MAC and MIB are exported to an external host
through the local UART port.
1.3 IEC 62056 (DLMS/COSEM)
IEC 62056 is a set of standards for electricity metering. The IEC 62056 standards are the
international standard versions of the DLMS/COSEM specification. DLMS or “device
language message specification” is the suite of standards developed and maintained by the
DLMS User Association. The DLMS User Association (UA) has established a D Type liaison
with IEC TC13 WG14, responsible for international standards for meter data exchange and
establishing the IEC 62056 series.
The DLMS UA provides maintenance, registration and conformance testing services for
IEC 62056 DLMS/COSEM. COSEM or “companion specification for energy metering”,
includes a set of specifications that defines the “transport and application layers” of the
DLMS protocol. The DLMS User Association defines the protocols in a set of four
specification documents, namely, Green Book, Yellow Book, Blue Book and White Book.
The Blue Book describes the COSEM meter object model and the object identification
system, the Green Book describes the architecture and protocols, the Yellow Book treats all
the questions concerning conformance testing, the White Book contains the glossary of
terms.
The standards included in this demonstration setup, on top of the IEC 61334, are:
– IEC 62056-4-32: Distribution automation using distribution line carrier systems -
Part 4: Data communication protocols - Section 32: Data link layer - Logical link
control (LLC)
– IEC 62056-53: COSEM application layer (this specification has now been
withdrawn by IEC)
– IEC 62056-61: Object identification system (OBIS)
– IEC 62056-62: Interface classes.