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24 Line Digital I/O Module (DIO-241)


24 Line Digital PC/104 I/O Expansion Module
(DIO-241)

  • 24 line digital input/output PC/104 expansion module
  • Stack-Through, 16 bit, PC/104 board
  • 3 ports of 8 input/output lines
  • Operating from +5V only
  • TTL-level inputs and outputs
  • MOSFET-based, high current outputs
  • Drive external relays, electronics etc.
  • Optically isolated inputs for direct activation from external sources
  • Based on proven industry standard 82C55A

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The DIO-241AxBx-N and DIO-241AxBx-P are 24-line Digital Input/Output PC/104-16 Expansion Modules with 24 programmable I/O pins. They are available with TTL-level Inputs/Outputs, and in several different combinations of this plus MOSFET-based, hi-current Outputs, for direct drive of external relays from either the Negative side (DIO-241AxBx-N) or the Positive side (DIO-241AxBx-P), electronics, etc., and/or Optically Isolated Inputs for direct activation from external sources.

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Based on the well proven industry standard 82C55A, the DIO-241AB are Stack-Through, 16-bit, PC/104 Board featuring 3 ports of 8 Input-Output lines each. Each line is individually programmable for use as either Input or Output (Mode 0) with direct bit Set/Reset capability, and is fully TTL compatible with 2.5 mA drive (sink or source) capability on all lines.

Operating from +5V only, the DIO-241AB is fully capable of operating in all three modes supported by the 82C55A:

  • Mode 0: Basic Input/Output
  • Mode 1: Strobed Input/Output
  • Mode 2: Strobed Bi-Directional Bus Input/Output

In full support of these three modes, the boards can be set to generate 2 different Interrupts, selectable by individual Jumpers from any of the available interrupts in the system. The interrupts are generated by either PC3/PC5 (Port A: IRQ-A or IBF-A - Jumper selectable) or PC0/PC1(Port B: IRQ-B or IBF-B - Jumper selectable).

The boards takes only 8 consecutive I/O Address spaces between either XXX0H and XXX7H or XXX8H - XXXFH (the I/O addresses shown in hexadecimal notation)! The Base I/O Address can be set at any available I/O address ending in "0" or "8" within the total 64K I/O Address space, and there is no aliasing:

  • IO Address Space: 0000H to FFF8H
  • Interrupts: IRQ 3, 4, 5, 6, 7, 9, 10, 11, 12, 14 or 15

All 24 lines are fully TTL compatible, with 2.5 mA Source/Sink capability, and are available for external connection via connector P1.

These boards may be ordered in several different population versions, based on combinations of TTL Input/Outputs and none, or four or eight 4A/40V/3W N-channel MOSFET or 4A/40V/3W P-Channel Outputs from Port A (available via Connector P2) and/or none, or four or eight 1500V Optically Isolated Inputs to Port B (available via Connector P3):

DIO-241AxBx-N
(Negative MOS Drive Outputs)

DIO-241A0B0-N Port A, Port B and Port C = TTL only
DIO-241A0B4-N Port A, B-upper and Port C = TTL
Port B-lower = 4 Optically isolated Inputs
DIO-241A0B8-N Port A, and C = TTL
Port B = 8 Optically isolated Inputs
DIO-241A4B0-N Port A-upper, Port B and Port C = TTL
Port A-lower = 4 N-MOSFET Outputs to GND
DIO-241A4B4-N Port A-upper, Port B-upper and Port C = TTL
Port A-lower = 4 N-MOSFET Outputs to GND
Port-B-lower = 4 Optically isolated Inputs
DIO-241A4B8-N Port A-upper and Port C = TTL
Port A-lower = 4 N-MOSFET Outputs to GND
Port B = 8 Optically isolated Inputs
DIO-241A8B0-N Port B and Port C = TTL
Port A = 8 N-MOSFET Outputs to GND
DIO-240A8B4-N Port B-lower and Port C = TTL
Port A = 8 N-MOSFET Outputs to GND
Port B-lower = 4 Optically isolated Inputs
DIO-241A8B8-N Port C = TTL
Port A = 8 N-MOSFET Outputs to GND
Port B = 8 Optically isolated Inputs

 

DIO-241AxBx-P
(Positive MOS Drive Outputs)

DIO-241A0B0-P Port A, Port B and Port C = TTL only
DIO-241A0B4-P Port A, B-upper and Port C = TTL
Port B-lower = 4 Optically isolated Inputs
DIO-241A0B8-P Port A, and C = TTL
Port B = 8 Optically isolated Inputs
DIO-241A4B0-P Port A-upper, Port B and Port C = TTL
Port A-lower = 4 P-MOSFET Outputs to V+
DIO-241A4B4-P Port A-upper, Port B-upper and Port C = TTL
Port A-lower = 4 P-MOSFET Outputs to V+
Port-B-lower = 4 Optically isolated Inputs
DIO-241A4B8-P Port A-upper and Port C = TTL
Port A-lower = 4 P-MOSFET Outputs to V+
Port B = 8 Optically isolated Inputs
DIO-241A8B0-P Port B and Port C = TTL
Port A = 8 P-MOSFET Outputs to V+
DIO-240A8B4-P Port B-lower and Port C = TTL
Port A = 8 P-MOSFET Outputs to V+
Port B-lower = 4 Optically isolated Inputs
DIO-241A8B8-P Port C = TTL
Port A = 8 P-MOSFET Outputs to V+
Port B = 8 Optically isolated Inputs

Note: Several lines on Port C may be used as control signals in Mode 1 and Mode 2.




DIO-241AxBx-N/P Board Outline




DIO-241AxBx-N/P Board Photo


DIO-241AxBx-N/P Connectors:

P1: Digital Input-Outputs, 2.5mA Sink/Source capability
P1, line 1 = Port A0 - P1, line 2 = GROUND
P1, line 3 = Port A1 - P1, line 4 = GROUND
P1, line 5 = Port A2 - P1, line 6 = GROUND
P1, line 7 = Port A3 - P1, line 8 = GROUND
P1, line 9 = Port A4 - P1, line 10 = GROUND
P1, line 11 = Port A5 - P1, line 12 = GROUND
P1, line 13 = Port A6 - P1, line 14 = GROUND
P1, line 15 = Port A7 - P1, line 16 = GROUND
P1, line 17 = Port B0 - P1, line 18 = GROUND
P1, line 19 = Port B1 - P1, line 20 = GROUND
P1, line 21 = Port B2 - P1, line 22 = GROUND
P1, line 23 = Port B3 - P1, line 24 = GROUND
P1, line 25 = Port B4 - P1, line 26 = GROUND
P1, line 27 = Port B5 - P1, line 28 = GROUND
P1, line 29 = Port B6 - P1, line 30 = GROUND
P1, line 31 = Port B7 - P1, line 32 = GROUND
P1, line 33 = Port C0 - P1, line 34 = GROUND
P1, line 35 = Port C1 - P1, line 36 = GROUND
P1, line 37 = Port C2 - P1, line 38 = GROUND
P1, line 39 = Port C3 - P1, line 40 = GROUND
P1, line 41 = Port C4 - P1, line 42 = GROUND
P1, line 43 = Port C5 - P1, line 44 = GROUND
P1, line 45 = Port C6 - P1, line 46 = GROUND
P1, line 47 = Port C7 - P1, line 48 = GROUND
P1, line 49 = +5V - P1, line 50 = GROUND

P2, DIO-241AB-N: 4A, 40V, 3Watt N-MOSFET Outputs controlled by Port A
P2, line 2 – 26 (all the even numbers) = V+ from external source
P2, line 1 = GND
P2, line 3 = GND
P2, line 5 = GND
P2, line 7 = N-MOSFET Output controlled by Port A0 - P2, line 2 to GROUND
P2, line 9 = N-MOSFET Output controlled by Port A1 - P2, line 4 to GROUND
P2, line 11 = N-MOSFET Output controlled by Port A2 - P2, line 6 to GROUND
P2, line 13 = N-MOSFET Output controlled by Port A3 - P2, line 8 to GROUND
P2, line 15 = N-MOSFET Output controlled by Port A4 - P2, line 10 to GROUND
P2, line 17 = N-MOSFET Output controlled by Port A5 - P2, line 12 to GROUND
P2, line 19 = N-MOSFET Output controlled by Port A6 - P2, line 14 to GROUND
P2, line 21 = N-MOSFET Output controlled by Port A7 - P2, line 16 to GROUND
P2, line 23 = GND
P2, line 25 = GND

P2, DIO-241AB-P: 4A, 40V, 3Watt P-MOSFET Outputs controlled by Port A
P2, line 2 – 26 (all even numbers) = GND from external source
P2, line 1 = V+ from external sourceP2, line 3 = V+ from external source
P2, line 5 = V+ from external sourceP2, line 7 = P-MOSFET Output controlled by Port A0 - P2, line 2 to V+P2, line 9 = P-MOSFET Output controlled by Port A1 - P2, line 4 to V+
P2, line 11 = P-MOSFET Output controlled by Port A2 - P2, line 6 to V+
P2, line 13 = P-MOSFET Output controlled by Port A3 - P2, line 8 to V+
P2, line 15 = P-MOSFET Output controlled by Port A4 - P2, line 10 to V+
P2, line 17 = P-MOSFET Output controlled by Port A5 - P2, line 12 to V+
P2, line 19 = P-MOSFET Output controlled by Port A6 - P2, line 14 to V+
P2, line 21 = P-MOSFET Output controlled by Port A7 - P2, line 16 to V+
P2, line 23 = V+ from external source
P2, line 25 = V+ from external source

P3: Optically Isolated Inputs connected to Port B
P3, line 1 = Opto Input 1 positive - P3, line 2 = Opto Input 1 negative to Port B0
P3, line 3 = Opto Input 2 positive - P3, line 4 = Opto Input 2 negative to Port B1
P3, line 5 = Opto Input 3 positive - P3, line 6 = Opto Input 3 negative to Port B2
P3, line 7 = Opto Input 4 positive - P3, line 8 = Opto Input 4 negative to Port B3
P3, line 9 = Opto Input 5 positive - P3, line 10 = Opto Input 5 negative to Port B4
P3, line 11 = Opto Input 6 positive - P3, line 12 = Opto Input 6 negative to Port B5
P3, line 13 = Opto Input 7 positive - P3, line 14 = Opto Input 7 negative to Port B6
P3, line 15 = Opto Input 8 positive - P3, line 16 = Opto Input 8 negative to Port B7

 

DIO-241-AxBx-N/P I/O Address Set-Up

1. First, you set the desired I/O Page Address on the Switch labeled ADDR 15-11 = Switch 1 (the bottom 6-ch switch in the picture above – covering I/O Address Lines 11 – 15). This switch decodes the upper 5 Address Lines - ADDR11 through ADDR15. With Switch 1, you select which I/O Page the board will be located on. The I/O Page Address can be set to:

0000H (default, factory setting)
0800H
1000H
1800H
...
E800H
F000H
F800H

2. Then, you set the desired I/O Base Address on the switch labeled ADDR 3-10 Switch = Switch 2 (the top 8-ch switch in the picture above – covering I/O Address Lines 3 – 10). This switch decodes the lower 8 I/O Address Lines (ADDR3 through ADDR10) above those actually used by the chip (ADDR0 through ADDR3). With Switch 2, you select which I/O Address within the I/O Page Address the board will be located on. The I/O Base Address can be set to any address ending on either "0" or on "8" and located between 0000H and 7F8H:

000H
008H
010H
...
7EFH
7F0H
7F8H

Note that the I/O Base Address is added to the I/O Page Address to form the full I/O Address:

Example 1:

I/O Base Address = 3F8H
I/O Page Address = 0000H
I/O Address = 03F8H

Example 2:
I/O Base Address = 3E8H
I/O Page Address = 3800H
I/O Address = 3BE8H

Example 3:
I/O Base Address = 7F8H
I/O Page Address = 0800H
I/O Address = 0FF8H

Example 4: To set up for I/O Address 03E8H Switch Settings (Note: within each switch bank, the lower switch number is the one located towards the middle of the board):

Switch Bank 1 (upper address – the bottom switch in the picture above):

6: ON (Note: This one is really: Don't care. It is not connected!)
5: (Address line 15) = ON (= 0)
4: (Address line 14) = ON (= 0) = 0 HEX
3: (Address line 13) = ON (= 0)
2: (Address line 12) = ON (= 0)
1: (Address line 11) = ON (= 0) = 3 HEX

Switch Bank 2 (lower address – the top switch in the picture above):
8: (Address line 10) = ON (= 0)
7: (Address line 9) = OFF (= 1)
6: (Address line 8) = OFF (= 1)
5: (Address line 7) = OFF (= 1)
4: (Address line 6) = OFF (= 1) = E HEX
3: (Address line 5) = OFF (= 1)
2: (Address line 4) = ON (= 0)
1: (Address line 3) = OFF (= 1) = 8 HEX

Example 5: To set up for I/O Address 02E8H Switch Settings (Note: within each switch bank, the lower switch number is the one located towards the middle of the board):

Switch Bank 1 (upper address – the bottom switch in the picture above):
6: ON (Note: This one is really: Don't care. It is not connected!)
5: (Address line 15) = ON (= 0)
4: (Address line 14) = ON (= 0) = 0 HEX
3: (Address line 13) = ON (= 0)
2: (Address line 12) = ON (= 0)
1: (Address line 11) = ON (= 0) = 2 HEX

Switch Bank 2 (lower address – the top switch in the picture above):
8: (Address line 10) = ON (= 0)
7: (Address line 9) = OFF (= 1)
6: (Address line 8) = OFF (= 0)
5: (Address line 7) = OFF (= 1)
4: (Address line 6) = OFF (= 1) = E HEX
3: (Address line 5) = OFF (= 1)
2: (Address line 4) = ON (= 0)
1: (Address line 3) = OFF (= 1) = 8 HEX

3. Now, determine if the board will be used in Mode 0, or Mode 1 or Mode 2 (see above), and if any Interrupts will be generated by the Mode used. The board can generate interrupts from the Port A Interrupt or the Port A Input Buffer Full outputs (IRQ-A and IBF-A), and/or from the Port B Interrupt or the Port B Input Buffer Full outputs (IRQ-B and IBF-B). See the detail documentation for the 82C55A for the operation of the various Modes possible, and the associated Interrupts generated. If Interrupts are required, set the source on Jumper 1 and/or Jumper 2, and then set the desired Interrupt to be activated by Jumper 3 and/or Jumper 4. Note that Jumpers 3 and 4 can access any of the interrupts in the system EVEN IF THESE ARE ALREADY IN USE!! It is, in other words, possible to share interrupts. Note that, if Interrupts are to be shared, then remember to set the SHARED INTERRUPT Jumpers J5 and/or J6 if necessary (See the detail documentation in the PC/104 Specification concerning Shared Interrupts)!

4. Now connect the wires to those items you want to control and/or read the state of with this board. Use P1 for TTL level signals, P2 for up to eight MOSFET, 4.2Amp/50V/3W Outputs controlled by Port A, and P3 for up to eight Optically Isolated Inputs connected to Port B. See the details below concerning pin-outs for P1, P2 and P3.

5. Mount the board onto the computer that will be interacting with it. Watch for bent pins in the PC/104 connectors and also for any short circuits.

6. Turn the system ON.

7. Once the desired operating system has been loaded, set the Control Word to the Control Register, located at an I/O Address equal to the I/O Address set above plus three:

Example:
I/O Base Address = 03F8H
Port A is at 3F8H
Port B is at 3F9H
Port C is at 3FAH
Control Register is at 3FBH

Example:
I/O Base Address = 02F8H
Port A is at 2F8H
Port B is at 2F9H
Port C is at 2FAH
Control Register is at 2FBH

See the detail documentation for the 82C55A concerning the various Modes and their associated Control Words. The Data Sheet can be accessed here:

INTEL: http://www.intel.com/design/archives/periphrl/docs/23125604.htm
HARRIS:
INTERSIL: http://www.intersil.com/data/fn/fn2969.pdf

7. If Interrupts will be used, write and install the Interrupt Routines that will be used to handle the Interrupts generated by the board.

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