Description
Key Technical Specifications
-
Model Number: VMIVME-2120-122
-
Manufacturer: GE Fanuc / VMIC (General Electric)
-
Channels: 64 open-collector outputs, grouped as 8 × 8-bit ports
-
Output Rating: 5-48 VDC, 600 mA sink per channel (max)
-
Isolation: 2 kV basic channel-to-bus; 500 VDC channel-to-channel
-
Data Path: 64-bit VME64x slave; 8-/16-/32-bit burst cycles
-
Protection: Clamp diodes for inductive fly-back, thermal shutdown, surge-current shutdown
-
Built-in-Test: BIT flag per channel; 10 ms response time
-
Addressing: 12-bit jumper-select, non-privileged I/O
-
Connectors: Front-panel 50-pin DIN (screw-terminal or ribbon)
-
Operating Temperature: –40 °C…+85 °C (military-grade)
-
Form Factor: 6U double-Eurocard VME64x
-
Status: Factory discontinued – new & tested spares available
GE VMIVME-7700RC
Field Application & Problem Solved
In the field the biggest headache is driving dozens of 24-48 VDC loads—contactors, brake solenoids, stack lights—without frying the back-plane or missing a command. The board solves that by giving you 64 open-collector outputs that can sink 600 mA at 48 VDC—enough to pull in a 5 A relay coil directly. You’ll typically find one per 6U crate on EX2100 or test-cell VME racks where you need to fire relays, brake solenoids, and stack lights in the same scan. Core value: it collapses 64 HV drivers, fly-back diodes, surge protection, and BIT status into one card you can swap while the turbine is on turning gear .
In the field the biggest headache is driving dozens of 24-48 VDC loads—contactors, brake solenoids, stack lights—without frying the back-plane or missing a command. The board solves that by giving you 64 open-collector outputs that can sink 600 mA at 48 VDC—enough to pull in a 5 A relay coil directly. You’ll typically find one per 6U crate on EX2100 or test-cell VME racks where you need to fire relays, brake solenoids, and stack lights in the same scan. Core value: it collapses 64 HV drivers, fly-back diodes, surge protection, and BIT status into one card you can swap while the turbine is on turning gear .
Installation & Maintenance Pitfalls (Expert Tips)
TTL Inputs Hate 24 V—Use a Divider
The control side is 5 V TTL; land 24 V on a data line and you’ll blow the buffer. Use the VMIC screw-terminal adapter with 4.7 kΩ / 1 kΩ dividers or add your own on the field strip.
The control side is 5 V TTL; land 24 V on a data line and you’ll blow the buffer. Use the VMIC screw-terminal adapter with 4.7 kΩ / 1 kΩ dividers or add your own on the field strip.
Channel-to-Channel Isolation Is 500 V – Don’t Ground Both Ends
If you tie the load return to a different ground you’ll circulate current and the BIT flag will flicker. Ground the load returns at one point only—preferably at the card common.
If you tie the load return to a different ground you’ll circulate current and the BIT flag will flicker. Ground the load returns at one point only—preferably at the card common.
Clamp Diodes Save Relays – Don’t Disable Them
The on-board fly-back diodes are there for a reason. If you disable them to speed up release time you’ll arc the driver and the channel goes low-impedance. Leave the diodes in circuit or add external zeners.
The on-board fly-back diodes are there for a reason. If you disable them to speed up release time you’ll arc the driver and the channel goes low-impedance. Leave the diodes in circuit or add external zeners.
Thermal Shutdown Latches – Cool Before Re-Enable
If you overload a channel (> 600 mA) the die hits 125 °C and the whole bank shuts down. You must remove load and let the heat-sink drop below 85 °C or the CPU will keep reading “OUTPUT FLT.”
If you overload a channel (> 600 mA) the die hits 125 °C and the whole bank shuts down. You must remove load and let the heat-sink drop below 85 °C or the CPU will keep reading “OUTPUT FLT.”
Spare Lead-Time Is 6-8 Weeks – Keep One on the Shelf
Factory stock is gone; new & tested spares are available but not overnight. If you burn a driver or crack a layer you’ll be down until the part arrives—keep one in stores or you’ll discover the weakness during the next grid event
Factory stock is gone; new & tested spares are available but not overnight. If you burn a driver or crack a layer you’ll be down until the part arrives—keep one in stores or you’ll discover the weakness during the next grid event
.
GE VMIVME-7700RC
Technical Deep Dive & Overview
Internally the card is 64 open-collector MOSFETs bolted to a VME64x slave interface. Each output sinks up to 600 mA when the gate is pulled low; the on-board thermal sensor shuts down the bank if die temp exceeds 125 °C. An opto-coupler drives the gate and reports BIT status; lose the opto and the CPU throws “OUTPUT FLT” even if the MOSFET is fine. No firmware—pure hardware—so you can swap it without reloading parameters; just remember to torque the front-panel screws or the connector will walk out on the first vibration cycle
Internally the card is 64 open-collector MOSFETs bolted to a VME64x slave interface. Each output sinks up to 600 mA when the gate is pulled low; the on-board thermal sensor shuts down the bank if die temp exceeds 125 °C. An opto-coupler drives the gate and reports BIT status; lose the opto and the CPU throws “OUTPUT FLT” even if the MOSFET is fine. No firmware—pure hardware—so you can swap it without reloading parameters; just remember to torque the front-panel screws or the connector will walk out on the first vibration cycle
.
