Hardware reference guide

7535 Hardware Reference Guide 25
Chapter 2: The Hardware
The Docking Port
Table 2.13 Docking Port Pinout
The 7535 distinguishes between devices on the docking port by reading the resistance
between pin 8 and ground on the docking port. These resistance values are as follows:
Table 2.14 Recognized Docking Port Resistor Values
Pin Number Purpose Notes
1 EXT_5V Switched 5V DC from 7535 (2 A max)
2 RXD RS232 RxD (7535 console port)
3 TXD RS232 TxD (7535 console port)
4 PWR_IN DC input to 7535 (9-20 V DC; 3.4 A max)
5 USB Host - USB host data - (to USB peripherals)
6 USB Host + USB host data + (to USB peripherals)
7 PWR_IN DC input to 7535 (9-20 V DC; 3.4 A max)
8 DOCK_ID The resistance between this pin and ground
identifies the device to which the terminal is
connected.
9 GROUND
10 USB_D- USB Client Data - (from USB host)
11 USB_D+ USB Client Data + (from USB host)
12 GROUND
Dock ID Resistor Value (Ohm) Connected Device
1 150k
259k
3 34.8k Powered Cradle
4 23.2k
5 16.2k PDM
611.8k
7 8.66k Port Replicator
8 6.34k
9 4.53k Combo charger/dock
10 3.01k
11 1.82k Quad dock
12 825