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1151E SCALER WITH ECL INPUTS

1151N SCALER WITH NIM INPUTS

FOR COUNTING AND PRE-SET SCALING IN CONTROL SYSTEMS AND EXPERIMENTS


The VME Models 1151E and 1151N count 16 sources of detector pulses and logic signals from physics research experiments or monitor/control applications. High counting rates and wide dynamic range are coupled to flexible control for count up or count down requirements.

Two versions are available depending on the input signal standard and connector selected. Model 1151N accepts standard NIM signals via LEMO style 00 connectors. Model 1151E accepts ECL signals and connectors, and is compatible with LeCroy high density ECLine instrumentation.

The readout of this instrument is in accordance with the VME Standard (ANSI/IEEE-1014). Therefore, this scaler may be controlled and read out with standard VME hardware systems (e.g. VME Master) and software packages.

FUNCTIONAL DESCRIPTION

A scaler is a pulse counter used to register pulses from discriminator and fast logic modules. Modern scalers usually do not have a visual readout display (i.e., they are "blind"), but rather communicate through a bus system (in this case VME) to a host computer.

Each input of the Model 1151 is capable of running at speeds up to 80 MHz. Each channel counts up to 2^32 (> 4 billion), high enough that it will not overflow under most applications.

In addition, any scaler may be used as a preset counter. A preset channel will count down from its initial value and then generates an OR'd NIM output pulse when it reaches zero.

The 1151 module is made up of two intermeshed systems. One section of circuits operates in real time to count the number of incoming pulses present at the front-panel coincident with a common gate signal. The gate signal is a required input signal. The gate is used to define a time window during which pulses on the 16 individual inputs will be counted.

The second section of the Model 1151 operates under control of the VME bus to setup the counters, and then read and/or reset their contents. The external logic must coordinate the interaction of these two systems to provide meaningful test data.

SPECIFICATIONS

Inputs: 16 scaler inputs. Model 1151N, NIM levels, Lemo 00 connector, 50 ohm termination. Model 1151E, ECL levels, 34-pin IDC header, 100 ohm termination.

Input Pulse Width: Minimum pulse width: 5 nsec. Maximum rate: 80 MHz.

Gate Input: NIM levels, Lemo 00 connector, 50 ohm termination.

CLEAR: Negative NIM level, Lemo 00 connector, 50 ohm termination. Minimum pulse width: 70 nsec.

TRIG OUT: NIM levels, Lemo 00 connector, output is generated when any counter reaches zero in countdown mode.

Configuration: 32-bit, bidirectional binary scalers; 16 independent channels with common gate input. Any one channel may be used as a preset counter. Preset output generates an OR'd NIM pulse output.

VME Control: A24 D16/D32 VME protocol. Module Address may be set with digital switches. VME functions include: Read scalers content, Write preset, General reset, 16-bit identification register.

Indicators: A channel LED lights up for 1 msec when a channel is counting. DTACK LED lights for 1 msec when the module is addressed. BERR lights for 1 msec when a module response error occurs.

Packaging: 6 U x 160 mm single-width VME, in conformance with VME specification (ANSI/IEEE-1014C).

Operating Temperature: 10 to 50 C.

Storage Temperature: -30 to 85 C.

Power: +5 V at 9.0 A, -12 V at 0.2 A.

Maximum Humidity: 80% non-condensing at 30 C.

Allocation of Address Space

This instrument was designed by CEN SACLAY, France.

Copyright© September 1995. LeCroy is a registered trademark of LeCroy Corporation. All rights reserved. Information in this publicaction supersedes all earlier versions.