CHAPTER 5
JUMPER SETTINGS


5.1 Introduction

The eleven jumper blocks on the PCCOM ISA bus 2 port RS422/RS485 adapter must be configured correctly in accordance with the operating system you are using.

JP1 (Jumper 1)
Determines the I/O address of the port 1.

JP2 (Jumper 2)
Determines the I/O address of the port 2.

JP3 (Jumper 3)
Select driver enable mode of channel 1.

JP4 (Jumper 4)
Select receiver enable mode of channel 1.

JP5 (Jumper 5)
Select high speed mode or normal speed mode.

JP6 (Jumper 6)
Enable selected interrupt. The selection of this jumper should correspond to the selection of JP9 and JP10.

JP7 (Jumper 7)
Select driver enable mode of channel 2.

JP8 (Jumper 8)
Select receiver enable mode of channel 2.

JP9 (Jumper 9)
Select interrupt for port 1. The range is from IRQ2 to IRQ15.

JP10 (Jumper 10)
Select interrupt for port 2. The range is from IRQ2 to IRQ15.

JP11 (Jumper 11)
Select number of delay wait states.

 
5.2 Configuration for Jumper

It is important to refer to the user manual supplied with your operating system to determine the correct configuration. Although we provide installation advice for various operating systems, it is not possible to cover all systems in this user guide. Please contact your supplier if you have any difficulties with configuration.

IMPORTANT: CARE MUST BE TAKEN IN SELECTING THE CONFIGURATION OF JUMPERS TO ENSURE YOU DO NOT DUPLICATE SETTINGS OF OTHER EQUIPMENT ALREADY INSTALLED IN YOUR COMPUTER. DUPLICATION OF SETTINGS WILL RESULT IN A MALFUNCTION OF ONE OR BOTH DEVICES.

Please refer to the following settings for each jumper block. If you are installing more than one board, do not duplicate jumper settings for any parameter.



1.    I/O Port Address



JP1 and JP2 are used to select UART I/O address for each port. Where JP1 is used to select port 1 address, JP2 is used to select port 2 address. Each JP contains A9 to A3 jumper pins and EN jumper pin.  The A9 to A3 are used to set I/O port address, when the corresponding pin is short means 0, otherwise no pin short means 1.  The figure above set the I/O address to 2A0H. The EN pin is used to enable the selected port, not short the jumper means enable the port, otherwise, if short the jumper means disable this port.

The setting examples of this board are:



2.    Interrupt Selection



JP9 is used to select interrupt for port 1 and JP10 is used to select interrupt for port 2. It can arrange these interrupts in any combination, this means it can set all ports in different interrupt, however, do not share the same interrupt. The figures shown above is to set interrupt on 5.

3.    Common IRQ



The JP6 is used to enable IRQ2 to IRQ15 bus lines.  Note that the selection of this jumper should correspond to the selection of the interrupts on the JP9 and JP10. For example, if you select IRQ5 and IRQ10 on the JP9 and JP10, you need short IRQ5 and IRQ10 of JP6.

4.    Select Wait State



The numbers of delay wait state are selected by JP11. Shorting position 1 means not wait CPU clock, shorting position 2 means wait 1 CPU clock, … etc.

5.    Select High Speed or Normal Speed Mode



The JP5 is used to select high speed mode or normal speed mode, the clock is 7.3728MHZ for high speed mode, and 1.8432MHZ for normal speed mode. For high speed mode, the baud rate speed up to 460K.



6.    Driver Mode Selection

JP3 and JP7 are used to select driver enable modes of channel 1 and 2 respectively. There are three enable modes:

a.    Always enable (for RS422)
This is required to set the always enable mode for RS422 applications.

b.   Enabled by RTS signal (for RS485)
When the signal is 1, the driver is enabled, otherwise when the signal is 0, the driver is disabled. To turn on the driver for RTS, you only need to output 3 to the address of base address plus 4. To turn off the drivers for RTS, you need to output 0 to the address of base address plus 4.

c.   Enabled by bit 0 (LSB) of control register (for RS485)
The address of the control register is base address plus 7. When the bit is set to 1, it enables the driver, otherwise when the bit is set to 0, it turns off the driver.

The driver mode selection of channel 1 is shown below:



Short JP3-1: driver always enabled.
Short JP3-2: enabled by RTS.
Short JP3-3: enabled by bit 0 of control register.
 
The driver mode selection of channel 2 is shown below:



Short JP7-1: driver always enabled.
Short JP7-2: enabled by RTS.
Short JP7-3: enabled by bit 0 of control register.

7.    Receiver Mode Selection

JP4 and JP8 are used to select the receiver enable mode of channel 1 and 2 respectively. There are two enable modes:

a.    Always enable (for RS422)
For RS422 applications, setting to always enable is required.

b.    Enabled by bit 1 (LSB) of control register (for RS485)
The address of control register is base address plus 7. When the bit is set to 1, the receiver is enabled, otherwise when the bit is set to 0, the receiver is turned off.

The receiver mode selection of channel 1 is shown below.



Short JP4-1: receiver always enable.
Short JP4-2: enabled by bit 1 of control register.
    
The receiver mode selection of channel 2 is shown below:



Short JP8-1: receiver always enable.
Short JP8-2: enabled by bit 1 of control register.


5.3 RS422 Mode



You can set (JP3,JP4) and (JP7,JP8) of this board to RS422 mode, then use PCCOM device driver and utilities in different operating systems.

The PCCOM software provides device driver for different operating systems under RS422 mode, please refer APPENDIX.


5.4 RS485 Mode

You can set (JP3,JP4) and (JP7,JP8) by yourself to control the driver mode and receiver mode (you can select enabled by RTS signal or enabled by control register pin). In this mode, you must control driver and receiver by your application software.

To write your own driver, please refer Chapter 7.


5.5 Standard COM1 and COM2 ports

If you want to set the adapter as standard COM1 and COM2, please refer the following settings.