23 GMC-I Messtechnik GmbH
8.
Communication
8.1.
Protocols
Each SMARTCONTROL interface can use several protocols. Simultaneous use of several protocols at the same
interface is not possible. The interfaces’ functions are configured in the SMARTCONTROL Manager.
8.1.1.
RS 232 / M-Bus
RS 232 / M-Bus is available at terminals (7), (9) and (10) [see section 6. , “Connections Overview,”] as a 9-pin D-
Sub plug. M-Bus compatible devices can also be connected to these terminals.
Supported baud rates (RS 232 and M-Bus): 300, 2400, 9600 and 19,200 baud
Note:
The following conditions must be fulfilled in order to allow for use of M-Bus devices:
M-Bus level converter with RS 232 port or optionally available M-Bus level converter 80 socket
module (article no. Z301Y) for the Gossen Metrawatt SMARTCONTROL V3.
Protocol: DIN EN 13757-3 (previously EN1434-3)
Unlimited readout interval (e.g. every 15 minutes)
M-Bus devices should be preprogrammed at the factory with unique addresses.
Maximum cable lengths for M-Bus networks must also be adhered to.
M-Bus level converters are available for 3, 20, 30, 60 or 250 devices. Up to 480 M-Bus devices can be addressed
by the SMARTCONTROL via M-Bus repeaters. However, we recommend limiting the size of M-Bus networks to
250 devices per SMARTCONTROL (interference, management, operating reliability).
8.1.2.
M-Bus Routing Function
With the help of MR firmware, the SMARTCONTROL can function as a router within an existing M-Bus network
[see section 9.1. , “Firmware Options”]. This is necessary in the event that the read-out intervals of the previous
installation are inadequate for energy management.
Interfaces (7) M-Bus and (9) FIELD2 are used to this end [see section 6. , “Connections Overview,”]. The level
converter is connected to interface (7), and the building management system to interface (9).
Access to the M-Bus by the building management system remains intact – the building management system has
precedence.
8.1.3.
RS 485 / Modbus RTU / Modbus TCP
RS 485 available at terminal (12) as 3-pole connection [see section 6. , “Connections Overview,”]. Firmware
option MO is required to this end [see section 9.1. , “Firmware Options”].
Supported baud rates (RS 232 and M-Bus): 1200, 2400, 4800, 9600 and 19,200 baud.
Modbus TCP is also supported. Terminal (11) is used to this end.
