Scale Controller; Usb; Leds - Pitney Bowes DM300c Service Manual

3 • Theory Of Operation
3.7 Scale
Controller

3.8 USB

3.9 LEDs

3-44
An optional, integrated platform scale connects to the main logic board
through a serial interface using a DB9 connector. This link provides the
weight information broadcast from the scale to the logic board's processor
using a 19,200 bit serial stream. The DB9 is connected to the main logic
board through connector J107. The DB9 connector provides 5V power to
the scale device.
The main logic board has three external USB ports:
• USB Slave — Type B plug: for PC Interface.
• USB Host 1 — Type A plug: for peripherals such as a printer or barcode
scanner.
• USB Host 2 — Type A plug: for peripherals such as a printer or barcode
scanner.
The service representative can check the status of USB devices using the
Service Diagnostics menu. See Chapter 6, Service Menus.
Main Logic Board (all models)
The main logic board has two status LEDS as shown in Figure 3-35.
• LED 1701 - Flashes fast. Indicates 5V present at the PHC board which
is sealed in the print carriage assembly.
• LED 1702 - "Heartbeat" lamp flashes once per second. It indicates 5V
present on the main logic board and that the microprocessor is running.
Feeder Board (DM400c/DM450c)
The feeder board for the DM400c/DM450c has a single LED as shown in Fig-
ure 3-41A. It indicates the board is receiving 5 volts from the power supply.
Feeder/WOW Board (DM475)
For the DM475, the feeder/WOW board (Figure 3-41B ) has four LEDs:
4. LED (red) – debug LED used by Engineering,
3. LED (orange) – indicates processor activity.
2. LED (green) - "Heartbeat" flashing once per second. It indicates that 5V is
present on the main logic board and that the microprocessor is running.
1. LED (dim red) – future use.
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)