Please Consult To Jumper And Switch Setting

JUMPER SETTING
The seven jumpers on 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)
Select which interrupt will be used in the range IRQ2 though IRQ7.

JP6 (Jumper 6)
Select number of delay wait states.

JP7 (Jumper 7)
Determines the address of the UARTs [I/O address]..

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 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
The JP7 is used to select the I/O port address. The I/O address mapping of each is shown below.
Mode1 JP7
 2
.
.
1
.
.
Mode2 JP7 2
.
.
1
.
.
Mode3 JP7 2
.
.
1
.
.
Mode4 JP7 2
.
.
1
.
.

Mode
 JP7-1
 JP7-2 Port1
 Port2
1
 short
 short 3F8-3FF
 2F8-2EF
2
 short open
 3E8-3EF
 2E8-2EF
3
 open short 1A0-1A7
 1A8-1AF
4
 open open


Factory setting is in mode 1 which are standard COM1: and COM2:.
  1. 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 interrupt 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:.
  1. The number of  delay wait states are selected by JP6. Shorting position 1 sets no 1 CPU clock, ...etc.
JP6
 1
 2
 3
 4
 5

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.
.
.
.
.
.
.
.
.

  1. 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 turn on the driver for RTS, you only need to output 3 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.
JP1
 1
 2
 3

.
.
.
.
.
.

Short JP1-1: driver always enabled.
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.
JP2
 1
 2
 3

.
.
.
.
.
.

Short JP2-1: driver always enable.
Short JP2-2: enabled by RTS.
Short JP2-3: enabled by bit 0 of control register.
  1. Receiver Mode Selection
JP3 and JP4 are used to select the receiver enable mode of channel 1 and 2 respectively. There are two enable modes:
a.  Always enable.
b.  For RS422 applications, setting to "always" enable is required.
c.  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, otherwise when the bit is set to 0, the receiver is turned off.

The receiver mode selection of channel 1 is shown below.
JP3
 2
 1

.
.
.
.

Short JP3-1: receiver always enable.
Short JP3-2: enabled by bit 1 of control register.

The receiver mode selection of channel 2 is shown below.
JP4
 2
 1

.
.
.
.

Short JP4-1: receiver always enable.
Short JP4-2: enabled by bit 1 of control register.
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