1. Overview

MVME162PA-252SE is a 6U dual-high VME bus single-board computer (SBC) produced by Motorola/Emerson. It belongs to the MVME162PA series of model 252 and is equipped with FPU, SCSI, 2×IP, single Ethernet, factory cooling fins, standard temperature range of 0~+70°C, and ruggedized soldering.

Processor: MC68040, 25 MHz, with FPU floating-point unit

Memory: 16MB DRAM (parity)

SRAM: 512KB (battery backup)

Flash: 1MB (162Bug firmware)

NVRAM/RTC: 8K×8, battery backup

VME: A32/D64, master/slave, system controller

I/O: single Ethernet, 2× serial ports, 2× IndustryPack, SCSI

Temperature: 0°C ~ +70°C (standard industrial grade)

Structure: S = factory metal heat sink, E = standard temperature version (non-wide temperature), L = non-rugged

2. Model Definition (252SE)

252: 2×IP, single Ethernet, SCSI, FPU, 16MB

S: with original factory metal heat sink

E: standard temperature (0~+70°C)

3. Hardware Specifications (Standard Configuration)

3.1 Processor and Memory

CPU: MC68040, 25 MHz, FPU built-in

L1 Cache: 8KB (instructions / data)

DRAM: 16MB, 32-bit, parity check

SRAM: 512KB, battery backup (power off retention)

Flash: 1MB, for 162Bug monitoring firmware

NVRAM: 8KB, with RTC, battery backup

3.2 Built-in I/O

Ethernet: 1×10 Mbps, DMA controller, AUI/10BASE-T

Serial Ports:

Serial Port 1: EIA-232-D, console (DTE)

Serial Port 2: EIA-232-D / EIA-422 (optional)

IndustryPack (IP): 2 slots, each with independent DMA

SCSI: single-ended SCSI-2, 32-bit DMA, supports hard drives / optical drives

VMEbus: A32/D64, master / slave, system controller

Timer: 6×32-bit, including watchdog (WDT)

3.3 Electrical and Environmental

Power Supply: +5V, typical 3.5A

Operating Temperature: 0°C ~ +70°C

Storage Temperature: -55°C ~ +125°C

Heat Dissipation: original factory aluminum alloy heat sink (passive cooling)

Vibration: standard industrial grade (non-reinforced, no L)

Size: 6U VME (233.4mm × 160mm)

Weight: approximately 1.0kg (with heat sink)

4. Panel and Connectors

4.1 Front Panel

S1 (ABORT): System abnormal interrupt key

S2 (RESET): Hardware reset key

DS1~DS4: Status indicator lights (power, operation, fault, network)

Console Port: DB9, EIA-232-D

Ethernet Port: RJ45 or AUI

IP Slot Cover: 2 pieces

4.2 Backplane Connectors (P1/P2)

P1: VMEbus standard signals (power, address, data, control)

P2: I/O expansion (serial ports, SCSI, Ethernet, IP signals)

5. Installation Steps

Anti-static: Wear anti-static wristband and operate on anti-static surface.

VME Cabinet Preparation: Confirm normal +5V, ±12V, GND power supply of the cabinet.

Inserting Cards:

Align with the upper and lower rails

Smoothly push into the P1/P2 backplane connectors

Tighten the front panel fixing screws

IP Module Installation (optional):

Insert the IP card into J1/J2

Fix the screws

Extrude the cables from the front panel slots

Connections:

Console: DB9 to PC serial port (115200, N81)

Network: RJ45 to switch

SCSI: Connect to SCSI hard drive / optical drive (terminal resistor correct)

Power On: Power on the cabinet first, then start the system.

6. Configuration and Jumper (Factory Default)

6.1 J20: SRAM Backup Source

Default: VME +5V standby power supply (1-3, 2-4 shorted)

Change onboard battery: 3-5, 4-6 shorted

6.2 J22: General Configuration Jumper (Read Only)

Factory: All shorted (00000000)

6.3 162Bug Basic Configuration (Power On Default)

Baud Rate: 115200

Data Bits: 8

Stop Bits: 1

Check: None Memory mapping: Flash

7. System startup and 162Bug

After power-on, it automatically enters the 162Bug monitoring program

Console display: MVME162Bug >

Common commands:

go: Start user program

md: Memory display

mm: Memory modification

reset: System reset

help: Help

8. Maintenance and fault troubleshooting

8.1 Daily maintenance

Keep the heat sink clean, without dust accumulation

Replace the SRAM/NVRAM backup battery annually

Check the backplane connectors for oxidation and looseness

8.2 Common faults

No power indicator: Check the power supply +5V, whether the board is securely plugged in

No startup, no console output: Check the serial cable, baud rate, 162Bug firmware

SCSI does not recognize the disk: Check the terminal resistor, SCSI line, ID address

No network connection: Check the network cable, IP address, 10/100M compatibility

9. Compatibility and replacement

Compatible with the same series: MVME162PA-252 / 252E / 252SE

Compatible pins but different functions: 244 series (no FPU, no SCSI, 4IP, dual network)

Can be directly replaced by model: MVME162PA-252SE (original model)