Products Overview

Processor Modules

I/O Expansion Modules


Enclosures & Accessories


Custom Products

COM-based SBCs

2-in-1 SBCs

Custom Solutions


Lifecycle Extension



Industrial Automation




Support Overview

Technical Resources

Contact Technical Support

Request an RMA

About Diamond Systems

The Diamond Advantage

Markets & Applications


Career Opportunities

3.5" Form Factor
COM Express
Single Board Computers
I/O Modules
Power Supplies
Single Board Computers
I/O Modules
Power Supplies
I/O Modules
Single Board Computers
PCIe MiniCard
PCIe MiniCard
PCIe MiniCard
PCIe MiniCard
PCIe MiniCard
I/O Modules
Single Board Computers
I/O Modules
Small form factor
Ethernet Switch Modules
Single Board Computers
Ethernet Switches
AGX Orin Solutions
ORIN Nano / NX
Nano and NX Solutions
AGX Xavier Module Solutions
TX2 / TX2i Module Solutions
MERCATOR II  PC/104-Plus Module with Quad 10/100 Ethernet and Digital I/O
Mercator II: Communications Modules, , PC/104-<i>Plus</i>
4 PCI-based 10/100 Ethernet ports
Pin header Ethernet connections
Ethernet activity LEDs for each port
24 digital I/O lines on ISA bus
Rugged design for harsh environments
Operating temperature -40ēC to +85ēC
Fully PC/104-Plus compliant mechanical design
Multiple assembly options: 1 or 2 Ethernet ports, with or without digital I/O


The Mercator II PC/104-Plus module integrates 4 PCI-based 10/100 Ethernet ports with 24 user-configurable digital I/O lines in the compact and rugged PC/104 format. This 2-in-1 combination of Ethernet and digital I/O can help lower the size and cost of your embedded system by eliminating one additional board from your PC/104 stack.

The Ethernet ports are driven by two dual Micrel KSZ8842 Mac + Phy PCI controller chips, two ports per chip, and are NE2000 compatible. Each chip has a unique MAC address; therefore, only two Ethernet ports are visible to the end user for active communication. The other two ports work in switch fashion to enable daisy chaining of networks with one port on the chip as an uplink to a network while the other port provides active communication on the network.

The 24 digital I/O lines are based on an 82C55 chip and feature programmable direction in 4- and 8-bit groups. All I/O lines contain user-configurable 10K ohm pull-up resistors for convenience.

Extended temperature capability (-40ēC to +85ēC) enables the board to operate in environments with extreme temperature swings, such as vehicles or outdoor installations. In addition, the board may be custom-configured with 0-ohm resistors in place of jumper blocks for increased ruggedness in high-vibration environments.

Diamond Systems offers appropriate mating cables for your convenience. Cable number C-PRZ-02 provides a panel-mountable RJ-45 connector for the Ethernet, and cable number C-26-18 is a 26-conductor ribbon cable for the digital I/O.

Configuration Options

Several features are configurable using either a dual-row 2mm size jumper block or a switch. Provision is made on the board for zero-ohm resistors to replace jumpers to enable a hard-wired configuration.

  • Digital I/O base address (8 address options with 3 jumpers)
  • Digital I/O configuration: pull-up enabled or disabled
  • PCI slot selection for each Ethernet port

Block Diagram

Mercator II: Communications Modules, , PC/104-<i>Plus</i>

I/O Headers

Ethernet Pin Header

This pin header is a locking 1x6 position right-angle header. The pinout is compatible with Diamond Systems' cable number C-PRZ-02, which provides a panel-mountable RJ-45 jack.

1 Common
2 RX-
3 Common
4 RX+
5 TX-
6 TX+

Digital I/O

The digital I/O is provided on a 26-pin (2x13) pin header with the following pinout.

C7 1 2 C6
C5 3 4 C4
C3 5 6 C2
C1 7 8 C0
B7 9 10 B6
B5 11 12 B4
B3 13 14 B2
B1 15 16 B0
A7 17 18 A6
A5 19 20 A4
A3 21 22 A2
A1 23 24 A0
+5V 25 26 Ground

Digital I/O Configuration

The following I/O addresses are selected with jumpers or 0-ohm resistors. All addresses are in hex.

A B C Address
In In In 200-203
Out In In 240-243
In Out In 280-283
Out Out In 2C0-2C3
In In Out 300-303
Out In Out 340-343
In Out Out 380-383
Out Out Out 3C0-3C3



Number of Ethernet ports 4
Protocol IEEE 802.3 10Base-T and 100Base-TX compatible
Maximum data rate 100Mbps
Digital I/O
Number of I/O lines 24
Direction Programmable: Ports A and B individually programmable for all input or all output.
Port C programmable in 4-bit groups for input or output
Input voltage Low: -0.5V min, 0.8V max
High: 2.0V min, 5.5V max
Output voltage Low 0.0V min, 0.4V max
High 3.0V min, Vcc - 0.4V max
Output current 2.5mA max, each line
Pull-up resistors 10KΩ pull-up
I/O headers
    Ethernet ports 6-pin straight male headers
    Digital I/O 26-pin (2x13) .025" square pin header on .1" centers
Mating cables
    Ethernet ports Cable number C-PRZ-02
    Digital I/O Cable number C-26-18
Dimensions 3.55" x 3.775" (PC/104-Plus standard)
Power supply +5VDC 10%
Operating temperature -40ēC to +85ēC
Operating humidity 5% to 95% noncondensing
PC/104-Plus bus Both ISA and PCI stackthrough headers installed



Mercator II
Available Models:
PC/104-Plus Quad 10/100Mbps Ethernet Module with 24 Digital I/O, extended temperature
Min Order Quantity
Please login or signup for an online quote request. | Sunnyvale, California USA | +1-650-810-2500 |