LeCroy 2232C 32-Input Differential ADC

* High Sensitivity: 12 bits or 0.025% resolution
* Two digitizing modes: Continuous Scan or Single Scan
* Asynchronous readout: any channel can be read at any time
* Independent measurement: operation same as 32 separate ADC's
* Bipolar or monopolar operation over a 10 volt range
* Differential Inputs: Common mode range of +/-5 volts
* Flexible readout: Block transfer (DMA) or address selection

The LeCroy Model 2232C is a 32-input, 12-bit ADC intended for use in general purpose voltage-monitoring applications. The >10Mohm inputs of the 2232C re- spond to voltages over a 10-volt range, converting them to proportional 12-bit digital data words. The output data format is use-selectable binary or two's com- plement. An on-board switch provides the choice of a monopolar mode, 0 to +10 volts, or a bipolar mode, -5 to +5 volts. The differential inputs suppress the con- tribution from common mode signals and high frequency noise is filtered out.

The voltage levels at the 32 inputs on the front panel connectors are converted sequentially, requiring 550 usec per channel for conversion and storage in the RAM (Random Access Memory). During readout the addressed 12-bit data word is placed on the Dataway without any interference of a store cycle, should one be present (asynchronous readout). In the Continuous Scan Mode each channel of the 2232C continuously updates its memory every 18 msec. Random access readout onto the CAMAC Dataway proceeds via the flexibility of reading in- dividual channels or subgroups of the 32 channels more frequently than others, permitting low maintenance items to be monitored compatibly with ones that demand a higher level of attention.

in the Single Scan Mode the CAMAC function F(25)-A (0)-N initializes the Analog Switch Address to Channel 1 and starts a single scan of all 32 channels. This may also be accomplished by applying a TTL pulse to a front-panel Lemo- type.connector (Scan Trigger). This mode thus permits all 32 measurements to be more clearly related in time to some external event or reference. LAM is generated after scan is completed and Q = 0 is generated after channel 32 is readout.

The 2232C finds useful application in the monitoring of power supply voltages, magnet currents, temperature or pressure transducers, and in a variety of other situations where computer-compatible high resolution measuring of dc voltages is desired.

Specifications

Analog inputs:

32 differential voltage-sensing inputs: direct-coupled; >10Mohms impedance; front-panel connectors mate with LeCroy Model CK2232 Connector Kit (2 required).

Full-Scale Range:

Bipolar Mode -- 5 to+5 volts between minus and plus input.
Monopolar Mode: 0 to+10 volts between minus and plus input.

Common Mode Range:

-+5 Volts (monopolar mode); +/-8 volts (bipolar mode).

Common Mode Rejection Ratio:

60 dB at 60 Hz.

Noise Immunity:

1kHz low pass filtering.

Integral Non-linearity:

+/- 1/2 count.

ADC Resolution:

12 bits (+0.025% relative accuracy). Input source impedance of <0.5Mohm is required for full accuracy over full scale range.

Accuracy:

+/-2.4mv.

Temperature Coefficient:

Accuracy, 30 PPM/degC, linearity 20 PPM/degC.

Mode Selection:

Single Scan/Continuous Scan and Bipolar/Unipolar Mode are both selected by on-board swit- ches. Binary/Two's Complement Data Format is jumper-selectable.

Conversion Time:

Continuous Scan Mode: continuously converted data always available for readout. Updated every 18 msec (550 usec/channel).
Single Scan Mode: 18 msec (550 usec/channel).

Readout Time:

Readout may proceed at the fastest rate permitted by the CAMAC standard at any time.

Data:

The proper CAMAC function and address gates the appropriate 12-bit word onto the R1-R12 Dataway bus lines. The user may select either binary format (straight binary in unipolar mode, off- set binary in bipolar mode) or 2's complement format (MSB inverted in bipolar mode, with read lines R13-R16 following MSB).

CAMAC Commands:

Q: No Q response is given for the first F(2)- A(0) command which is used to set up the DMA mode. The next 32 F(2)- A(0) commands will generate a Q = 1. A 34th F(2)- A(0) command will generate a Q = 0 to indicate end of valid data. A Q = 1 is returned on F(8)- A(0) if and only if the in- ternal LAM is asserted. A Q = 1 is returned for all other valid CAMAC commands.

L: In the signal scan mode only, a Look-At-Me signal is generated after all 32 inputs have been digitized until a module CLEAR. LAM is disabled for the duration of N and cleared by Z, C or F(9)- A(0).

X: An X = 1(Command Accepted) response is generated when a valid F, N, and A command is applied.

F(0)- A(i);i = 0-15, read the data word from input (i + 1). Requires N.
F(1)- A(i);i = 0-15, read the data from input (i + 17). Requires N.
F(2)-A(0): First F(2) sets up DMA mode and initiates readout address to zero. Successive F(2) commands then read all 32 registers sequentially starting with input 1 and progressing to input 32 (33rd F(2)). Requires A(0), N and S2. Upon receipt of 34th F(2)- A(0), a Q= 0 response is given and the unit returns to the continuous scan mode. Facilitates DMA transfers.
F(8)-A(0): Asserts 'Q' if LAM is set.
F(9)-A(0): Reset LAM. Terminate scanning.
F(24)-A(0): N Disables LAM.
F(25)-A(0): Initiates Single Scan of all inputs beginning with input 1. Requires N and S2. Note: It is recommended to "initiate" with F25 after power turn-on when in Continuous Scan Mode. F(26)-A(0): N Enables LAM.

Scan Trigger:

Logical "one" TTL pulse (>+ 2.0 volts) of duration >100 nsec applied to front-panel Lemotype connector initiates single scan of all 32 inputs beginning with input 1.

Packaging:

In conformance with CAMAC standard for nuclear modules (ESONE Committee Report EUR 4100 and IEEE #583). RF-shielded CAMAC #1 module.

Power Requirements:

+6V at 700 mA
+24V at 50 mA
- 24V at 50 mA

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Specifications
Analog inputs:	32 differential voltage-sensing inputs: direct-coupled; >10Mohms impedance; front-panel connectors mate with LeCroy Model CK2232 Connector Kit (2 required).
Full-Scale Range:	Bipolar Mode -- 5 to+5 volts between minus and plus input. Monopolar Mode: 0 to+10 volts between minus and plus input.
Common Mode Range:	-+5 Volts (monopolar mode); +/-8 volts (bipolar mode).
Common Mode Rejection Ratio:	60 dB at 60 Hz.
Noise Immunity:	1kHz low pass filtering.
Integral Non-linearity:	+/- 1/2 count.
ADC Resolution:	12 bits (+0.025% relative accuracy). Input source impedance of <0.5Mohm is required for full accuracy over full scale range.
Accuracy:	+/-2.4mv.
Temperature Coefficient:	Accuracy, 30 PPM/degC, linearity 20 PPM/degC.
Mode Selection:	Single Scan/Continuous Scan and Bipolar/Unipolar Mode are both selected by on-board swit- ches. Binary/Two's Complement Data Format is jumper-selectable.
Conversion Time:	Continuous Scan Mode: continuously converted data always available for readout. Updated every 18 msec (550 usec/channel). Single Scan Mode: 18 msec (550 usec/channel).
Readout Time:	Readout may proceed at the fastest rate permitted by the CAMAC standard at any time.
Data:	The proper CAMAC function and address gates the appropriate 12-bit word onto the R1-R12 Dataway bus lines. The user may select either binary format (straight binary in unipolar mode, off- set binary in bipolar mode) or 2's complement format (MSB inverted in bipolar mode, with read lines R13-R16 following MSB).
CAMAC Commands:	Q: No Q response is given for the first F(2)- A(0) command which is used to set up the DMA mode. The next 32 F(2)- A(0) commands will generate a Q = 1. A 34th F(2)- A(0) command will generate a Q = 0 to indicate end of valid data. A Q = 1 is returned on F(8)- A(0) if and only if the in- ternal LAM is asserted. A Q = 1 is returned for all other valid CAMAC commands. L: In the signal scan mode only, a Look-At-Me signal is generated after all 32 inputs have been digitized until a module CLEAR. LAM is disabled for the duration of N and cleared by Z, C or F(9)- A(0). X: An X = 1(Command Accepted) response is generated when a valid F, N, and A command is applied. F(0)- A(i);i = 0-15, read the data word from input (i + 1). Requires N. F(1)- A(i);i = 0-15, read the data from input (i + 17). Requires N. F(2)-A(0): First F(2) sets up DMA mode and initiates readout address to zero. Successive F(2) commands then read all 32 registers sequentially starting with input 1 and progressing to input 32 (33rd F(2)). Requires A(0), N and S2. Upon receipt of 34th F(2)- A(0), a Q= 0 response is given and the unit returns to the continuous scan mode. Facilitates DMA transfers. F(8)-A(0): Asserts 'Q' if LAM is set. F(9)-A(0): Reset LAM. Terminate scanning. F(24)-A(0): N Disables LAM. F(25)-A(0): Initiates Single Scan of all inputs beginning with input 1. Requires N and S2. Note: It is recommended to "initiate" with F25 after power turn-on when in Continuous Scan Mode. F(26)-A(0): N Enables LAM.
Scan Trigger:	Logical "one" TTL pulse (>+ 2.0 volts) of duration >100 nsec applied to front-panel Lemotype connector initiates single scan of all 32 inputs beginning with input 1.
Packaging:	In conformance with CAMAC standard for nuclear modules (ESONE Committee Report EUR 4100 and IEEE #583). RF-shielded CAMAC #1 module.
Power Requirements:	+6V at 700 mA +24V at 50 mA - 24V at 50 mA