LG Electronics 120S user manual Write RTC data, Date expression, Saturday

Chapter 5 Power Supply / CPU

(2) Read RTC data from special register

Special register Area		Description			Data
(Word)		Upper byte		Lower byte	(BCD format)
F053	Lower 2 digits of year		Month		H0207
F054	Day		Hour		H2313
F055	Minute		Second		H5020
F056	Higher 2 digits of year			Date	H2002

Example : 2002. 07. 23. 13:50:20, Tuesday

2) Write RTC data

There is two ways to write new RTC data to the CPU.

The first one is using a graphic loader (KGLWIN). For detailed information, refer the user’s manual of KGLWIN.

The second one is write sequence program. By switching a special bit on, user can replace the current RTC data with the reset data stored in a specified memory area. The followings are the memory address of preset data and an example program.

Data register Area		Description			Data
(Word)		Upper byte		Lower byte	(BCD format)
D4993	Lower 2 digits of year		Month		H0207
D4994		Day		Hour	H1011
D4995	Minute		Second		h5324
D4996	Higher 2 digits of year		Date		H2001

Example : 2002. 7. 10. 11:53:24, Monday

* M1904 : RTC data change bit

When the M1904 bit is switched on, the new data in D4993 ~ D4996 will be moved to F53 ~ F56. After data is moved, M1904 has to be switched off immediately because current data will be updated every scan while M1904 is on.

3) Date expression

Number	0	1	2	3	4	5	6
Date	Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday

REMARK

1)If RTC stops or error occurs, write new data to the RTC then error is called off.

2)There is no written clock data in the RTC when shipped.

3)Before using RTC module, write clock data to the RTC first

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