
Technical Data
CAN-CBM-Clock
Hardware Manual • Doc.-No.: C.2836.21 / Rev. 1.3
Page 13 of 34
2.5 RTC
The CAN-CBM-Clock module is equipped with an internal RTC (Real Time Clock). The RTC is
powered by a lithium coin cell. For a battery change the case of the CAN-CBM-Clock module has to
be opened.
NOTICE
The battery change may only be carried out by qualified personal! It is recommended to
send the CAN-CBM-Clock module to esd for the battery change after 5 years.
Frequency tolerance of the
RTC
maximum (at 25
¨
C): ±20ppm
Hold-up time
Minimum: 5 years, typical: 8 years
Battery
Type: Coin cell, 3 V, Lithium-battery (CR1220)
Self-discharge: typical 1% per year at 23
¨
C
Storage life: typical 10 years
Table 5: Data of the real time clock
2.6 Software
The CAN-Clock module operates with the CANopen-protocol according to CiA Draft-Standard
401.
Times are transmitted to the CAN bus in CANopen-format
coding of time:
in milliseconds after midnight
coding of date:
in days since January 1st, 1984
(please refer to the software manual of the CAN-Clock module)