Another from the 1980's

How could we do this today? I have a need for it. 100 channels.

Portable data logger

A line of full featured, rugged data gathering products that tie directly to thermocouples or voltage output devices has been introduced by MetraByte. The DDL-400 data logger allows the user to configure systems to meet specific application requirements in the lab, factory, or field. The IBM compatible programmable, menu driven data logger offers 16 analog input channels, 4 digital inputs, and 16 alarm outputs. A sealed membrane keyboard controls functions such as interval, Hi/Lo alarm limits, channel select, and time settings. The LCD readout shows channel data, limits, and status. Each data logger requires an I/O panel, a slide in module that has 16 single ended inputs for a thermocouple voltage signal, as well as 16 TTL logic level outputs and 4 input channels. Each channel is configured by a 10 position range switch. Every alarm is independantly checked at full speed at least every 4 seconds. Limit values are stored in non-volatile memory.

Expansion from standalone to complete system is simple and easy. As many as 5 data loggers (for a total of 80 channels) can be networked together using the RS422 ports on the unit and wiring to the PC.

No programming experience is required for set up. Once data is taken it can be sent to a printer, or sent to one of the DB-2000 data buffers. Suggested applications are temperature monitoring, field environment experiments, benchtop data gathering, industrial equipment monitoring, and remote data gathering.

Prices for the expansion data logger range from $995 to $1295. The DDL-SW application software costs $995. The TCV-16 I/O module is $345. A complete line of accessories, including cables, adapters, memory buffer, battery backup, rack mounting kits, driver, and relays is also available. The total to get started is $2,335.

MetraByte Corp 440 Myles Standish Blvd Taunton, MA 02780

Do a search with key words Arduino data logger.

100 channels ... you'll need more than 1 MCU.

Not really: ATMega2560 has 86 IO lines (10 8-bit ports, 1 6-bit port) So with chip or two for multiplexing/demultiplexing can get to 100 IO easy.

Which parts do you need? (analog inputs, alarm outputs. logging, thermocouple support, range switches, LCD for each 16 ports?) You can certainly still buy similar things to connect to PC class computers (eg http://www.dataq.com ) To a large extent, the price is heavily dependent on how flexible and "robust" those inputs are. a $1000 dataq unit will hardly ever explode because you misconnected it, which I'm not sure you can say about a $30 Arduino.