Siemens SIMATIC S5 CP 523 Manual page 149

Communications Mode
7.4.1 Reading the Status Byte, the Status of the Peripheral Device and the
Current Clock Data
As soon as job request 0000
transfer memory:
• The status byte
• The status of the peripheral device
• The current clock data
The return info is the same for job requests:
• 1000 : "Set clock"
H
• 90XX : Transfer parameter setting
H
Table 7-22. Status Information and Current Clock Data
Byte
0 Status byte
1 Status of the peripheral device
Bits 4 to 7:
Bits 0 to 3:
1=Sunday, 2=Monday, 3=Tuesday, 4=Wednesday
5=Thursday, 6=Friday, 7=Saturday
2 Current day
3 Current month
4 Current year
5 Current hour
6 Current minute
7 Current second
Status byte (byte 0)
The status byte provides information on
• errors during data interchange between CP and I/O device
• the status of a CPU job
• the status of the CP 523
• battery backup
The status byte is divided into two half-bytes. Both half-bytes are independent of each other. They
can be combined in any way.
7-44
has been transferred to the CP, the CP writes the following into the
H
(byte 0)
(byte 1)
(bytes 1 to 7)
Meaning
Peripheral device not ready
Current day of the week
Peripheral device ready
24 h clock
12 h clock a.m.
12 h clock p.m.
CP 523
Possible Values
7.24
0X
BCD
1X
BCD
X1 to X7
BCD BCD
01 to 31
BCD BCD
01 to 12
BCD BCD
00 to 99
BCD BCD
00 to 23
BCD BCD
01 to 12
BCD BCD
81 to 92
BCD BCD
00 to 59
BCD BCD
00 to 59
BCD BCD
EWA 4NEB 811 6044-02a