Fluke Helios Plus 2287A, 1500 I/O Frontend, Teardown and Test

[madsbarnkob]

Teardown, cleaning and test of a Fluke Helios Plus 2287A Data Acquisition Frontend and 2181A Extender. The Frontend and extender features two Fluke 2280A-161 High Performance A/D Converter 2280A161 cards and nine 20-channel RTD/Resistance Scanner modules, for a total of 180 inputs in this setup with a Frontend and Extender.



The main CPU is a Texas Instruments TMS9995, which essentially is a TI-990 Microcomputer on a single IC.



Fluke 2280A-161 High Performance A/D Converter 2280A161 has its own smaller microcontroller to respond and time the measurements, in correspondence to the commands from the CPU module. The local controller is a Toshiba TMP80C39AP-6 which is a 8-bit controller running at 6 MHz with 27 I/O and 8 built-in timers.

A Intersil HD3-6402 UART Universal Asynchronous Receiver Transmitter is used for the communication through the mainframe backplane



The 20-channel RTD/Resistance Scanner 2280A153 modules only has enough logic ICs to drive the 20 reed relays and communicate with the High Performance ADC 2280A161 card.



All pictures can be found at: https://kaizerpowerelectronics.dk/electronics/fluke-helios-plus-2287a-1500-i-o-frontend-teardown-and-test/