Micros Systems Workstation 5 - Cash Drawer Closed Detection; Cash Drawer Interface

2-30 Workstation 5 Field Service Guide
Workstation 5 System Board Technical Descriptions
Point Of Sale Interfaces
Cash Drawer Interface (REF: ABRD88 - Sheet 30)
The system board supports two cash drawers /w standard 4-pin DIN
connectors. The cash drawer interface is similar to the Workstation 4 LX
system board.
Active Low outputs from the Super IO, CD_OPEN_A# and CD_OPEN_B#
are inverted by U11E and U11F before driving the CLK inputs of dual
flip-flop U13. The pulse width at the output of each flip-flop is about 70ms,
determined by the 1N4148 diodes, 1MΩ resistors, and 0.1µf capacitors.
CD_OPEN_A drives pin 1 of U44, while pin 2, CD_OPEN_DELAY
prevents the drawer from opening when power is applied to the unit.
CD_OPEN_B drives pin 1 of U45, while pin 2, CD_OPEN_DELAY
prevents the drawer from opening when power is applied to the unit.
The output of each AND gate drives a SI4410DY N-Channel enhancement
mode field-effect transistor. 1N4002 Diodes D4 and D2 protect each
transistor from the back EMF created by the solenoid as the transistor
switches off.
The +12V supply, VCC12 conducts through D17 when the +24V circuit is
not used through self-resetting fuse F7. If the +24V cash drawer setting in
the BIOS is active, diode D17 isolates VCC12.
Cash Drawer Closed Detection
Each drawer contains a SPST switch positioned to detect the drawer
open/closed status. The interface is configured to provide a High on
CD_ST_A or CD_ST_B at pin 4 of CN1 and CN2 when the drawer is open
or not installed and a Low on the status line when the drawer is closed. R21
and R28 ensure each line is high if a drawer is not connected. The cash
drawer closed logic can be inverted through a registry setting. See below
for more information.
The API checks a system registry key at start-up to determine the drawer
open/closed logic levels. HKEY_LOCAL_MACHINE -> UWS4DRIVER
-> CONFIGURATION ReverseCDStatus=0 is the default setting.
The default setting causes the API to report the drawer open/closed logic
levels mentioned above. If ReverseCDStatus=1, the API inverts the drawer
open/closed logic levels before passing them on to the application
software. The registry setting would be changed from the default only if
using a cash drawer with reversed cash drawer closed logic.