3516 32-channel, Scanning A/D Converter




The Model 3516 is a single-width CAMAC module which converts 32 analog voltages into their equivalent digital values. This module contains a high-resolution analog-to-digital converter capable of resolving one part in 65,536. The inputs are scanned, and the results are stored in a 32-word memory which can be read via the Dataway. The number of active (scanned) channels is software programmable. There are two software-selectable scan modes, continuous and single-scan. With continuous mode, CAMAC Read cycles are asynchronous with the conversion process, eliminating any overhead due to testing for a converter busy. If it is desirable to synchronize scanning and reading, single-scan mode can be used. In this mode, a LAM status is set after the last channel has been converted. In addition, the external trigger input may be used to synchronously trigger a single scan on multiple 3516s.

The 3516 contains a 4-bit, 32-word memory which can be loaded on a channel-by-channel basis from the Dataway with an appropriate gain factor applied to each differential input signal. Eleven gain factors, from one to 1024, are available in a binary progression. This allows one 3516 to measure a wide variety of input signal types (such as thermocouples, RTDs, high-level inputs, etc.). The V2B option features a single-pole, lowpass filter at the input of each channel. These filters provide a -3dB cutoff frequency of 6Hz.

Once channel scanning is initiated, each channel’s input is selected, the preloaded gain factor is applied to it, the amplified signal is converted, and the resultant binary information is stored in the on-board memory. Conversions take place at the rate of one every 250 microseconds (all 32 channels in eight milliseconds). The memory is configured in a dual-ported fashion to facilitate retrieval of data with CAMAC block transfer operations. The 3516 is precalibrated for +/-10 volt inputs.


All input signals are brought to the module through a pair of Amp 36-contact connectors mounted on the front panel. These connectors mate directly with KSC Model 5944-Z1A mating connectors and with the 5855-Series of cable assemblies. The external trigger is brought in through a single-pin LEMO connector. Alternately, the 3516 may be strapped to accept an external trigger from the Dataway P1, P2, or P3 lines. An N LED flashes whenever the module is addressed, and an ACTIVE light indicates when the module is powered and scanning is activated. A LAM LED is illuminated when a LAM request is pending.


To facilitate the use of this module in temperature monitoring systems, both Channels 1 and 17 can be strapped to receive an isothermal reference from a Model 1991-V1A 16-channel Isothermal Panel. Alternatively, these channels may be used to monitor any analog data.

For monitoring 4-20 mA control loop signals, the standard practice is to mount a precision 250-ohm resistor external to the module allowing the 3516 to be removed from the circuit without disturbing the current loop. The KSC Model 1854 Termination Panel may be used for this purpose.


+24 volts — 80 mA

–24 volts — 70 mA

+6 volts — 1.5 A

Weight: .89 kg. (1 lb. 14 oz.)


Model 3516-V3A — 32-channel, Scanning A/D Converter

Model 3516-V3B — 32-channel, Scanning A/D Converter with Filter


Model 5944-Z1A Mating Connector

Model 1854-A2A Termination Panel and 5855-B30J Cable (two cables required)

Model 1991-V1A 16-channel Isothermal Panel