Communications Mode
CP 523
7.4.1
Reading the Status Byte, the Status of the Peripheral Device and the
Current Clock Data
As soon as job request 0000
H
has been transferred to the CP, the CP writes the following into the
transfer memory:
•
The status byte
(byte 0)
•
The status of the peripheral device
(byte 1)
•
The current clock data
(bytes 1 to 7)
The return info is the same for job requests:
•
1000
H
:
”Set clock”
•
90XX
H
:
Transfer parameter setting
Table 7-22. Status Information and Current Clock Data
Possible Values
Byte
Meaning
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
0
Status byte
7.24
1
Status of the peripheral device
Bits 4 to 7:
Peripheral device ready
Peripheral device not ready
Bits 0 to 3:
Current day of the week
1=Sunday, 2=Monday, 3=Tuesday, 4=Wednesday
5=Thursday, 6=Friday, 7=Saturday
0X
BCD
1X
BCD
X1
BCD
to X7
BCD
2
Current day
01
BCD
to 31
BCD
3
Current month
01
BCD
to 12
BCD
Current year
00
BCD
to 99
BCD
Current hour
24 h clock
12 h clock a.m.
12 h clock p.m.
00
BCD
to 23
BCD
01
BCD
to 12
BCD
81
BCD
to 92
BCD
4
5
6
Current minute
00
BCD
to 59
BCD
Current second
00
BCD
to 59
BCD
7
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
EWA 4NEB 811 6044-02a