Elvaco CMi4140, User Manual

Page: 21 / 26

CMi414
0 User’s Manual English
CMi414
0 User’s Manual English
page | 21 (26) [2020-06]
V1.1
6.7.3 Meter communication error message
The payloads using M-Bus encoded data uses the Function field of the DIF to indicate errors. In this case
it is set to “value during error state” (M-Bus standard EN 13757-3:2013) and the value sent should not be
used. A typical case for this is when the module is unable to communicate with the meter and retrieve
meter values, in which case all the fields in the payload have the DIF indicating “value during error state”.
In case of erroneous data or if the module is unable to communicate with meter, bit 4-5 of the bit of the
DIF code (first byte of each index field) will be set to 11b. For example, a DIF code of 0x02 will be set to
0x32 in case of error. (This applies to all message format except JSON.) For message format JSON, the
actual value will be replaced with “null” in case of error state. If no meter communication is possible at all,
all fields have this error indication set.
6.8 Downlink
CMi4140 supports configuration via downlink, i.e. sending commands to an end-device via the LoRaWAN
network.
Note that this feature should only be used sparingly due to bandwidth consideration.
Communication via downlink is sent on port 2 and can only be made in a short window after an uplink
transmission from module to server. Therefore, time-critical communication should not be performed over
downlink.
Downlink commands are structured according to the following format:
“0x00” "TLV
" " Number of bytes in
configuration" "Configuration". For a complete description of all available downlink commands, see Table
16 .
Field name TLV Number of
bytes in
configuration Configuration Example
Configuration
lock 0x05
0x01 0x00 = Locked
0x01 = Open 0x00050101
(Enables configuration
lock)
Transmit
interval 0x06
0x02 0xNumber of minutes
between transmission
(lsByte -> msByte) 0x0006021E00
(Sets the Tx interval to
30 minutes)
Message
format 0x07
0x01
0x15 = Message format
Standard
0x16 = Message format
Compact
0x17 = Message format
JSON
0x18 = Message format
Scheduled-daily redundant
0x19 = Message format
Scheduled-Extended
0x1A = Message format
Combined heat/cooling
0x1B = Message format Heat
Intelligence
0x000701016
(Sets the message
format to compact)
EcoMode 0x0F
0x01 0x00 = Disable EcoMode
0x01 = Enable EcoMode
0x000F0100
(Disables EcoMode)
Set Time
Relative
0x13 0x04 0xNumber of seconds*
(lsByte -> msByte)
*Negative numbers
supported.
0x0013043C000000
(Adds 60 seconds to the
current time)
0x0013043C000080