MA-025
–
DGA 900 Operator Guide
–
Rev 2.0
12-Apr-19
Page 85 of 92
Appendix D
Time Sync Implementation
The product has a time-sync feature that allows users to synchronize the clock. This
Appendix explains the data format options for the “time sync” and its implementation.
D.1
Time Format
Under the standard Modbus® register list, the timing is defined in Table D-1.
Table D-1: Timing
Register
Permissions
Group
Size
Description
Data Format
1200
R/W
4*
UTC Clock: Years
YYYY (BCD)
1201
UTC Clock: Months, days
MMDD (BCD)
1202
UTC Clock: Hours, minutes
HHMM (BCD)
1203
UTC Clock: Seconds, Day of week
(0-6, 0 Sunday)
SSWW (BCD)
This R/W (read/write) register is in BCD format (Binary Coded Decimal). Some systems are
not compatible with this data format. *The time registers can be written separately in 5
second intervals in any order.
D.2
UNIX® Epoch register
A UNIX Epoch register was added to the host board firmware (v1.12.2) to make systems
integration easier in cases of system incompatibility. Both register formats (BCD & UNIX)
will be maintained in future firmware versions and both affect the same single clock. The
details of the UNIX time registers are listed in Table D-2.
Table D-2: UNIX time registers
Register
Access
Flags
Version
Storage
Class
Effect
After
Name
Description
Data
Format
1197
rg2,wg2
1.12.2
RAM
immediately
RTC_UNIX_
TIME
Current Time UTC
in UNIX format
32-bit
integer
1198
These registers are readable and writable, but should be written together as a single 32-bit
value.
D.2.1
UNIX Time Format
The number of seconds from the UNIX epoch time of Jan 1st 1970 00:00:00.
D.2.2
UNIX Time Example
For reference, the time on a device is reported in the UTC format on the HMI as 11/29/2017
00:00:00 BST and the corresponding value in the registers mentioned above is
1511913600.
