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7106 Discriminator Latch


- 16 Channels in a Single Width CAMAC Module 
- 140 MHz Rate Capability less than 8nSec Double Pulse Resolution
- Deadtimeless Updating or Time-Over-Threshold Operation 
- Synchronized Operation - Latched Output Mode 
- Internal DATA LATCH Captures Output States at End of SYNC Period 
- Common Fast Veto 
- Individually Masked Inhibiting
- Local or Remote Modes of Operation
- Linear Summed Output Useful for Majority Logic Decisions
- Threshold range -10mV to -1Volt - CAMAC Programmable 
- Threshold Level Readable from CAMAC Regardless of Mode 
- Test Features Allow Easy Testing of All Channels 
- Two Differential ECL Outputs per Channel 


The model 7106 is a high-performance, 16 channel leading edge discriminator packaged in a single width CAMAC module. The most commonly asked for features have been designed into this discriminator, making it an extremely versatile instrument. The 7106 threshold is variable from -10mV to -1.033 Volt by either a front panel control when in LOCAL mode, or via CAMAC when in REMOTE mode. 

The module always powers up in LOCAL mode which helps eliminate the possibility of having all the thresholds going to minimum, sometimes causing damage to sensitive detectors if the trigger rate were too high. The threshold can be measured at the front panel test point (voltage is ten times threshold) or may be read via CAMAC (10-bit ADC with 1mV resolution) independent of the MODE of the module. 

A linear summed output provides a -1mA current for each channel that is active. By feeding the SUM output into a discriminator, the user can perform prompt majority logic decisions, selecting events based upon a minimum or maximum number of channels fired, often greatly simplifying the logic required for complex triggers. Inhibiting of the discriminator can be performed by applying a NIM signal to the VETO input connector, which inhibits all 16 channels simultaneously. 

Individual channels may be masked (REMOTE mode only) by writing into the internal mask register via CAMAC. The mask register is disabled whenever the 7106 is in LOCAL mode. The outputs can be retimed by applying a NIM signal to the SYNC input connector. The state of all channels will be held for the duration of the SYNC input signal. This feature allows the channel profile to be maintained while an event trigger processor captures the profile. In addition to freezing the outputs of the discriminator, the SYNC signal also causes the states of all outputs to be transferred into an internal 16-bit register for subsequent readout via CAMAC. 

The CAMAC read of the DATA LATCH returns (in addition to 16-bits of data) a Q=1 response, if and only if, a SYNC signal has occurred since the last read of the DATA LATCH. A Q=0 indicates that the DATA LATCH has not been updated since the last CAMAC read. The 7106 can be used as an updating or Time-Over-Threshold (TOT) discriminator as selected with the front panel Update/TOT switch. The updating output is variable from 4.5nSec to 110nSec and will be extended should an input occur while the output is active. In the TOT mode, the output will equal the Time-Over-Threshold of the input or the Preset output duration, whichever is longer. 

A special TOT mode can be enabled (via internal jumper, one per channel) such that the output duration will equal 5nSec or the Time-Over-Threshold of the channel, whichever is longer. A mixture of both types of TOT mode can be used within one module. A front panel LED is ON when the UPDATE mode is selected. Connecting a NIM signal (5nSec minimum duration) to the TEST input connector will cause those channels not MASKED off to be triggered just as if a normal input signal exceeded the threshold of each channel. A CAMAC command has been included (F25) which when executed will cause all channels not MASKED off to be triggered in the same manner as the TEST input. 

There is one difference, the CAMAC command (F25) will only execute if the 7106 is in the REMOTE mode. The Q response to the F(25) command will indicate whether or not the test pulse was generated. Q =1 means it was. The TEST feature, used in conjunction with the MASK register, allows user defined output patterns to be generated for testing complex triggers. The front panel switch labeled CAMAC/LOCAL determines which features are programmable. When the switch is in the LOCAL position, CAMAC can only monitor the 7106 for example, read THRESHOLD voltage and DATA LATCH contents. While in LOCAL the effects of the MASK register and internal Threshold DAC are disabled, but both registers can still be written into and read out. Switching between LOCAL and CAMAC will not alter the contents of any internal register. 

When the front panel switch is in the CAMAC position, the mode of the 7106 (LOCAL or REMOTE) is programmable via CAMAC. When programmed into the REMOTE mode, the THRESHOLD is controlled by an internal 10-bit DAC, and the MASK register is enabled. CAMAC can also force the 7106 into the LOCAL mode which is identical to positioning the switch to LOCAL with one exception and that is that CAMAC can force the unit back into the REMOTE mode (only if the switch is in CAMAC). A front panel LED is ON when the 7106 is in the REMOTE mode. 

711 Leading Edge Discriminator


- Six Channels In Single Width NIM Module 
- 150 MHz Rate Capability 
- Burst Guard Capability 
- Deadtimeless Updating Outputs 
- Fast Summed Output 
- Fast Veto and Bin Gate Inhibiting 


The Model 711 is a high-performance, six channel, leading edge discriminator packaged in a single width NIM module. It features independent threshold and width controls, updating or burst guard operation, a fast veto for inhibiting, a prompt linear summed output, and a versatile output configuration with five outputs per channel. The 711 has high input sensitivity of -10mV variable to -1Volt via a 15-turn front panel control. A front panel test point on each channel provides a DC voltage equal to ten times the actual threshold to insure accurate settings. 

A two position switch permits the 711 to be used as either a conventional updating discriminator or, when in the Burst Guard position, an updating discriminator with the time-over-threshold feature. As an updating discriminator the output width is variable from 4nSec to 1mSec via a front panel screwdriver adjustment. Should inputs occur at time intervals less than the double-pulse resolution (typically 6nSec), the unit will not respond. In the Burst Guard mode when inputs occur that are less than the discriminator resolving time, the output will be extended until the trailing edge of the last pulse within the burst. Inhibiting of the discriminator can be accomplished in two ways. 

A front panel LEMO input accepts a NIM level pulse for fast simultaneous inhibiting of all six channels. Secondly, a slow bin gate via the rear panel connector inhibits the module and is enabled or disabled from a rear panel slide switch. A unique summed output common to all six channels delivers -1mA of current for each activated channel, thus allowing a fast decision to be made on the number of channels simultaneously hit. Up to 18 channels can be "OR'D" directly by cable to other summed outputs providing a versatile scheme to form a trigger. 

The 711 has five high-impedance current switching outputs per channel. They are configured as two pairs of double-amplitude bridged outputs and one complemented NIM output. When only one output from a bridged pair is used, a double-amplitude NIM pulse (-32mA) is generated for driving long cables. Two normal NIM levels are produced when both of the bridged pairs operate into 50 ohm loads. The output risetimes and falltimes are typically 1nSec, and their shapes are virtually unaffected by the loading conditions of the other outputs. 


PHOTOMULTIPLIER PREAMPLIFIER 16 DC to 275 Single-width CAMAC module containing sixteen preamps each with 10X voltage gain. Designed for fast photomultiplier tube detectors in systems not requiring NIM instrumentation. 


Fixed Gain of 10 Non-Inverting Wideband DC to 275 MHz High Density - 16 Channels per CAMAC Slot Low Noise - Less than 25 µV RMS Cascadable for Gains of 100 Excellent Stability, Gain and Offset All Inputs and Outputs Protected DESCRIPTION The Model 7176 provides 16 independent, direct-coupled amplifiers in a single width CAMAC module. 

Each channel has a non-inverting voltage gain of 10, operates from DC to 275 MHz and drives a 50 ohm output. It's designed for use with fast photomultiplier detectors having negative going output pulses. This amplifier exhibits excellent DC and high frequency stability. Two channels can be cascaded to obtain voltage gains of 100 while maintaining good pulse fidelity without significant overshoot or baseline drift. 

Each channel has an internal DC offset adjustment allowing for compensation of the DC output due to variations of input source impedance or grounding differences. The output stage is a low-impedance voltage source design with short-circuit protection. No damage will occur from overloading or continuous shorts to ground. 

The output stage is designed to drive either one or two 50 ohm loads, however, unused outputs may remain unterminated with no adverse effects.

7194 Gate/Delay Generator


  • Four Independent Gate/Delay Channels 

  • Wide Range, 50 nSec to over 10 Seconds 

  • NIM, TTL Inputs; NIM, TTL, ECL Outputs 

  • Deadtimeless Operation 

  • Set/Reset Flip-Flop Mode 

  • Remote Programming via a 0 Volt to 10 Volt Input 

  • Easily Configured as an Oscillator or a Pulser


The Model 7194 Quad Gate/Delay Generator is a CAMAC version of the popular NIM 794 packaged in a double width CAMAC module. In monostable mode, Gate/Delay periods may be adjusted either locally or remotely from less than 50nSec to more than 10 seconds. Each channel also operates in a Set/Reset flip-flop mode. A bright LED indicates an active gate condition. Versatile input and output structures provide compatibility with NIM, ECL, and TTL standards. Further flexibility is afforded by programming jumpers mounted on the printed circuit board. These jumpers allow selected inputs and outputs to be assigned alternate logic functions or polarities.

Time-Base Section

he model 7194 time-base circuit is non-updating and exhibits essentially no deadtime. Monostable Gate/Delay periods are selected by a combination of the RANGE switch and an analog programming input. A monitor test point provides a 0 to 1 Volt output which is proportional to the Gate/Delay period. Setting the Gate/Delay period with an oscilloscope is easily accomplished by pushing the TRIGGER push-button. Depressing this switch for more than 0.5 seconds causes the time-base to retrigger at a 1 KHz rate. In the bistable mode, the Gate/Delay period is equal to the interval between the arrival of the trigger and reset functions. The DELAY output always occurs at the trailing edge of the GATE output and it's output width may be adjusted by a front panel potentiometer.

Input Section

There are three ways to trigger the Model 7194: (1) TRIGGER Input; (2) OR Input; (3) TRIGGER push-button. These functions are enabled in both monostable and bistable modes.

(1), The TRIGGER input is compatible with both positive TTL levels and negative NIM logic. This input presents a high impedance to positive signals and 50 ohms to negative signals. The time-base triggers on the leading edge of the input pulse regardless of its logic type. The gate period is independent of the TRIGGER pulse width.

(2), OR is a negative NIM logic input which is configured with program jumpers. The OR input is always logically OR'ed with the time base output. Assuming a quiescent time base, the GATE output width is equal to the OR input width. A program jumper enables an alternate OR mode in which the OR input also triggers the time-base. This mode produces a GATE output equal to the width of the OR input or the preset time, whichever is greater. An additional jumper allows OR to be a high impedance or 50 ohms. Note that the high impedance OR input allows multiple channels or multiple modules to be easily daisy-chained and triggered from a single source.

(3), The TRIGGER push-button offers two operating modes for manual triggering. In the single trigger pulse mode, a single output is produced by pushing and releasing the switch in less than 0.5 seconds. In retrigger mode, by pushing and holding the switch for more than 0.5 seconds produces a continuous pulse train of 1 KHz as long as the push-button is depressed.

In the bistable (FF) position, when the channel is triggered or SET, it remains in that state until reset by the negative NIM compatible RESET input or the RESET push-button. The TRIGGER and OR inputs are inhibited from setting the channel when RESET is present. The RESET input is enabled only in the bistable mode.

INHIBIT is a negative NIM compatible input. All outputs are forced to their quiescent state whenever INHIBIT is present. GATE transitions resulting from INHIBIT do not generate DELAY outputs.

A special feature of the Model 7194 is the ANALOG PROGRAMMING input. Enabled by program jumpers, each input accepts 0 to +10 Volt levels and produces a 5% to 105% adjustment of the selected range. The analog voltage is received differentially to relieve the noise and common mode offsets associated with long cable runs.

Output Section

Each channel has five (5) outputs. GATE, complemented GATE, and DELAY are negative NIM current source outputs governed by the trigger rules described above. TTL is a TTL compatible output which can be assigned to either the GATE or DELAY function. A second jumper associated with TTL provides a true or complement feature. ECL is a differential ECL output conforming to CERN Note EP 79-01 and is jumper programmed to be identical to either GATE or DELAY outputs.

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