Avery Berkel CX20 SERIES, Service Manual

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23 — RS232 Interface PCB (CX20 W)
23–3 CX20/CX30/CX34 Service Manual
23.1 General
The RS232 interface PCB provides an interface with a wide range of wrapping
machines. It supplies RS232 ASCII serial data for the ULMA 200 Series which
enables selection of an internal wrapper program or initialising the wrapper start
cycle. The RS232 interface PCB also provides a bi–directional interface which
allows communication with an external printer for an Italian ADF type machine.
The RS232 interface PCB has the following features:
filtering for the remote load cell
label taken detection
’Wrapper Start’ output
RS232 serial interface for communication with the ULMA UL200 Series of
machines
all ’outside world’ signals are electrically isolated by relay or optocouplers
analogue input filter
RTS and CTS provide the optional controls of ’Wrapper Ready’ and ’Scale
in Control’.
Figure 23.1 RS232 Interface PCB
PL1: 16–way IDC to CX20 W
PL14 comms controller
TB2: to remote transducer
TB1: to A/D PCB
PL7: 10–way IDC to CX20 W PL18
PL4: 4–way molex – label
taken reflective photocell
PL5: 2–way molex to
CX20 W PL12 – label
taken relay
PL2: 3–way molex to CX20 W
PL9 – cash drawer
PL3: 3 pin DIN to old style
wrapper – only 1 and 2 used
PL8: 14–way IDC to
9–way D–type plug RS232
serial channel ULMA or
ADF printer
Label taken detection is provided by a reflective photocell, connected to the
RS232 interface PCB, which detects when a label has not been taken.
Operation of the wrapper is then inhibited.
Wrapper start output is provided by a relay contact closure which initiates a
wrapper start. (Only for old style wrapper systems, for example, ULMA Chikit.)