CHAPTER 5
JUMPER SETTINGS
5.1 Introduction
The seven jumpers onf the PC
COM RS422/RS485 adapter must be configured
correctly in accordance with the operating system you are using.
JP1
(Jumper 1)
Select driver enable mode of channel 1.
JP2 (Jumper 2)
Select driver enable mode of channel 2.
JP3 (Jumper 3)
Select receiver enable mode of channel 1.
JP4 (Jumper 4)
Select receiver enable mode of channel 2.
JP5 (Jumper 5)
Selects which interrupt will be used in the range IRQ2 throuth IRQ7.
JP6 (Jumper 6)
Select number of delay wait states.
JP7 (Jumper 7)
Determines the address of the UARTs [I/O address].
Select driver enable mode of channel 1.
JP2 (Jumper 2)
Select driver enable mode of channel 2.
JP3 (Jumper 3)
Select receiver enable mode of channel 1.
JP4 (Jumper 4)
Select receiver enable mode of channel 2.
JP5 (Jumper 5)
Selects which interrupt will be used in the range IRQ2 throuth IRQ7.
JP6 (Jumper 6)
Select number of delay wait states.
JP7 (Jumper 7)
Determines the address of the UARTs [I/O address].
5.2
Selection of Jumper Settings
It is important to refer to the
user manual supplied with your
operating system to determine the correct configuration.
IMPORTANT: CARE MUST BE TAKEN
IN SELECTING THE CONFIGURATIONOF 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. If you are
installing more than one board do not duplicate jumper settings for any
parameter.
1. I/O Port
Address
The JP7 is used to select the I/O port address. The I/O address mapping of each port is shown below.
Factory setting is in mode 1 mode 1 which are standard COM1: and COM2:.
2. Interrupt Setting
JP5 is used to select the interrupt level. To short the R and C side means to select interrupt the level of channel 1, shorting the L and C side selects the inter-rupt level of channel 2.
In a standard PC system, COM1: (3F8-3FF) and COM2: (2F8-2FF) generate interrupts on IRQ4 and IRQ3 respectively. Factory settings of this jumper are IRQ4 and IRQ3, which corresponds to COM1: and COM2:.
3. Delay Wait States
The number of delay wait states are selected by JP6. Shorting position 1 sets no wait CPU clock, shorting position 2 sets wait 1 CPU clock, ... etc.
4. Driver Mode Selection
JP1 and JP2 are used to select driver enable modes of channel 1 and 2 respectively. There are three enable modes:
a. Always enable.
This is required to set the always enable mode for RS422 applications.
b. Enabled by RTS signal.
When the signal is 1, the driver is enabled, otherwise when the signal is 0, the driver is disabled. To trun on the driver for RTS, you only need to output 3 to the address of base address plus 4. To turn off the driver for RTS, you need to output 0 to the address of base address plus 4.
c. Enabled by bit 0(LSB) of control register
The address of 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.
The driver mode selection of channel 2 is shown below.
The JP7 is used to select the I/O port address. The I/O address mapping of each port is shown below.
Factory setting is in mode 1 mode 1 which are standard COM1: and COM2:.
2. Interrupt Setting
JP5 is used to select the interrupt level. To short the R and C side means to select interrupt the level of channel 1, shorting the L and C side selects the inter-rupt level of channel 2.
In a standard PC system, COM1: (3F8-3FF) and COM2: (2F8-2FF) generate interrupts on IRQ4 and IRQ3 respectively. Factory settings of this jumper are IRQ4 and IRQ3, which corresponds to COM1: and COM2:.
3. Delay Wait States
The number of delay wait states are selected by JP6. Shorting position 1 sets no wait CPU clock, shorting position 2 sets wait 1 CPU clock, ... etc.
4. Driver Mode Selection
JP1 and JP2 are used to select driver enable modes of channel 1 and 2 respectively. There are three enable modes:
a. Always enable.
This is required to set the always enable mode for RS422 applications.
b. Enabled by RTS signal.
When the signal is 1, the driver is enabled, otherwise when the signal is 0, the driver is disabled. To trun on the driver for RTS, you only need to output 3 to the address of base address plus 4. To turn off the driver for RTS, you need to output 0 to the address of base address plus 4.
c. Enabled by bit 0(LSB) of control register
The address of 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 JP1-1 : driver always
enabled.
Short JP1-2 : enabled by RTS.
Short JP1-3 : enabled by bit 0 of control register.
Short JP1-2 : enabled by RTS.
Short JP1-3 : enabled by bit 0 of control register.
The driver mode selection of channel 2 is shown below.
Short JP2-1 : driver always
enabled.
Short JP2-2 : enabled by RTS.
Short JP2-3 : enabled by bit 0 of control register.
Short JP2-2 : enabled by RTS.
Short JP2-3 : enabled by bit 0 of control register.
5. Receiver Mode Selection
JP3 and JP4 are used to select
the receiver enable mode of channel 1
and 2 re-spectively. There are two enable modes:
a. Always enable.
For RS422 applications, setting to "always: enable is required.
b. Enabled by bit 1(LSB) of control register.
The address of control register
is base address plus 7. When the bit is
set to 1, the receiver is enabled, therwise when the bit is set to 0,
the receiver is turned off.
The receiver mode selection of channel 1 is shown below.
Short JP3-1 : receiver always
enable.
Short JP3-2 : enabled by bit 1 of control register.
Short JP3-2 : enabled by bit 1 of control register.
The receiver mode selection of channel 2 is shown below.
Short JP4-1 : receiver always
enable.
Short JP4-2 : enabled by bit 1 of control register.
Short JP4-2 : enabled by bit 1 of control register.
