Siemens SIMATIC S5-115U, Руководство пользователя

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S5-115U Manual Integral Real-Time Clock
13.5 Programming the Integral Clock
Transferring Settings to the Clock
• Settings are stored in the clock data area with Transfer operations (cf. Table 13-3).
• The AM/PM flag (bit No. 7) is only significant in 12-hour mode.
Bit 7=1 PM
Bit 7=0 AM
• Clock data must be transferred in BCD.
Note
The "KC" data format loads a BCD constant into ACCUM 1 and is therefore especially
suitable for entering clock settings.
• If a setting is not to be transferred, identify the corresponding byte with the number "255
D
"
or "FF
H
". The value of this variable in the clock is then retained when the clock is set.
• Once you have transferred the settings to the clock data area, you must set bit 2 of the status
word before the clock can accept the clock data.
• Incorrect settings are flagged in the status word by setting bit 0. The clock continues to ope-
rate with old values.
Example: Transferring new settings (clock time/date) to the clock, using the programmer.
Setting the clock with the following data: Tue 01.03.88; 12.00.00. The status word is assigned to
flag word 10 and the clock data is stored in DB2 from data word 0. The settings for the clock data
are transferred:
• With the "FORCE VAR" programmer function if the PC is in RUN Mode
• With the "FORCE VAR" programmer function if the PC is in "STOP" mode and status word
bit 4=1.
Note
When using the "FORCE VAR" function, you must enter the clock data first and then
the status word.
EWA 4NEB 811 6130-02b
13-13