Print Mode
CP 523
6.5
Processing Job Requests in Print Mode
The CP 523 handles data transfer with the printer autonomously. Data transfer between the CPU
and the CP 523 must always be initiated by the CPU. The CP 523 has an eight-byte transfer
memory, which can be used by the CPU and the CP 523.
Figure 6-6. Schematic Representation of Job Order Processing in Print Mode
Send
print requests
S5-CPU
CP 523
Peripheral
device
Receive
print requests
Transfer
memory
Serial
interface
a a
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a a
a a
a a
a a
a a
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a a
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a a
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Message
buffer
Internal bus
Job
buffer
The CPU transfers the following in the transfer memory
•
Word 0:
the job request, e.g.: "Print message text No. 20"
•
Words 2,4,6:
further necessary or possible information on the job,
e.g.: value of a variable to be inserted in the message text at printout.
The CP 523 writes the following to the transfer memory after a job has been executed:
•
Byte 0:
Status of the module
•
Byte 1:
Status of the printer and current day
•
Byte 2 to 7:
The remaining current clock data
6-30
EWA 4NEB 811 6044-02a
