User's Manual

Psion Teklogix 7535 G2 Hand-Held Computer Service Manual 11
Chapter 1: Introduction
Ports
the Docking Port Services driver and is turned on only after the device is attached and a valid Dock ID
is detected.
Console Port
The ‘console port’ is a serial text-mode interface to the 7535 G2’s system. Commands can be issued to
the 7535 G2’s bootloader software through this interface. The console port is shared by the 7535 G2’s
main processor and its peripheral controller; when the main processor is active, it is connected to the
console port by default. This console port is COM3 under Windows CE .NET.
The console port uses a standard 3-wire serial interface (TxD, RxD, GND). Signals levels are standard
RS-232 levels. This port is provided as a 9-pin D-connector on the Portable Docking Module.
USB Host Port
The USB host interface complies with USB specification 1.1 and provides a “high-speed” connection to
external devices and hubs. Power for external devices is provided through the docking port’s power
output pins. The OHCI driver is in charge of the USB Host interface.
USB Client Port
The docking port provides a USB client interface to connect the 7535 G2 to a USB host computer
or hub. The 7535 G2 acts as a USB serial device attached to COM4 for Windows CE.NET. The 7535 G2
also can act as a USB client (a Mass Storage Device), when its bootloader is running, to allow software
updates via USB.
Dock ID
By reading a resistance value, the 7535 G2 can identify the device attached to the docking port. The
Docking Services driver reads the ID, identifying the device, checks the registry to see which driver to
load, then loads the appropriate driver.
1.4.11.13 The Tether Port
Figure 1.4 The Tether Port
The tether port allows an external non-decoded scanner, a serial scanner, or a USB client device to be
connected to the terminal through a single connector. Generic serial devices, such as printers, GPS
receivers, and other serial devices, are also supported.
Tether Port