Avery Berkel CX20 SERIES, Service Manual

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2 — General and Technical
2–14 CX20/CX30/CX34 Service Manual
In receipt mode, when transaction has been accepted (keyboard input), the
microprocessor sums all the component transactions and transmits the result for
display. This procedure continues for each transaction until the end of sale,
then the microprocessor drives the printer to print the totals and transmits the
results for display. When the operation is complete and the printer has finished,
the microprocessor drives it to advance the ticket roll; this enables the ticket to
be torn off by the operator and issued as an itemized receipt.
The unit includes a variety of connectors enabling connection to various external
or network functions.
Details of unit operation are contained in the User Handbooks applicable to the
unit. See Overview section for more details.
2.3 Networking
Refer to Section 21.
Each unit is capable of being networked as either a MASTER or a SLAVE unit.
2.4 Built–in Test Equipment
The unit includes diagnostic software written in the EPROM firmware. This can
be accessed for maintenance use by the setting of a DIL switch. The diagnostic
software contains a number of diagnostic routines which the engineer can
choose to run (refer to Section 8). Program progress and results are displayed
on the unit displays. The unit also will display error messages generated from
firmware in response to certain conditions of operator error or equipment failure:
the list of error messages is shown in Section 10.