Alpha-Log
–
User manual
LSI LASTEM SRL
INSTUM_03388
Page 62 / 116
4.2
Insights the Alpha-Log functionalities
4.2.1
Communication protocols
Alpha-Log is provided with proprietary protocol SAP (
Simple ASCII Protocol
). It provides configuration and
transfer service of the acquired and processed data to the instrument, and the control commands of the
devices connected to it. Communication works through Com2 port
(6)
. Communication parameters are
editable by 3DOM and default ones are: Speed: 115220 bps, Parity: None, Stop bits: 1, Flow control: None.
Alpha-Log implements Boschung protocol (pavement sensor for road traffic applications) and part of
industrial protocol Modbus RTU and Modbus TCP, both Master and Slave. See manual
INSTUM_03762
for
more information on Modbus Slave.
4.2.2
Internal clock/calendar
Alpha-Log is equipped with an internal clock with backup battery. This clock is used for elaborations, alarms
and system events dating and for the scheduling of other activities such as the processed files transmission
on one or more FTP servers, the measures acquisition, the actuators activation, etc. Therefore, keeping the
clock synced is important.
Alpha-Log synchronizes the clock in the following circumstances:
➢
When it receives the configuration by SSH connection from the PC. In this case the data logger lines up
with the PC clock. Update is immediate.
➢
If at least one NTP server is specified in its configuration. An Internet connection is required. The check
and the possible alignment take place every 10 hours. This time, which cannot be modified, is a
compromise between the need to update the time according to the accuracy of the internal clock and
the energy and data traffic used for this operation.
➢
By command from the 3DOM software. The data logger instantly synchronizes with the PC clock in
this case too.
Starting from version 2.01 of Alpha-Log, it is also possible to change the system time through the
special command available with SSH connection (for example through the program
PuTTY
). It
requires the IP address of the data logger as a parameter. Log in as
root
and enter the password
indicated on the back label of the instrument, then enter the command:
/usr/local/bin/sbctimesync "yyyy-MM-
ddThh:mm:ss”
.