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CHAPTER 12
TRANSIAC MODEL 2008 TRANSIENT WAVEFORM RECORDER (DTIZ)
TRANSIAC Model 2008
8-Bit 20Mhz
Transient Waveform Recorder
INTRODUCTION
The TRANSIAC model 2008 is a high speed, medium resolution
waveform digitizer capable of storing up to 8192 samples.
In the sampling (CVT) mode the analog signal is sampled on
the positive edge of the clock (internal or external),
converted to a digital number and stored in memory. This
sequence is performed continuously until a stop trigger is
detected after which the programmed number of post-trigger
samples are digitized. After sampling is completed data
is either displayed on an oscilloscope or read by the
computer.
CAMAC COMMANDS
o F0 A0: Read control register. (R1-R9)
pretrigger samples, memory size and
sample period. See Table 1
o F2 A0: Read waveform data. Q-0 returned after
last data word.
o F3 A0: Read Module ID (16-bits, R1=LSB)
This has been set in hardware to 2008(dec)
o F8 A0: Test LAM, Q=1 returned if LAM on.
o F9 A0: Initiate module and start sampling.
o F10 A0: Reset LAM.
o F11 A0: Computer single sample.
o F16 A0: Write control register (W1-W9).
Pretrigger samples,memory size, and
sampling period (W1-W9).
(TABLE 1)
TRANSIAC MODEL 2008 TRANSIENT WAVEFORM RECORDER (DTIZ) Page 12-2
Register Value CAMAC lines
W9 W8 W7 W6 W5 W4 W3 W2 W1
R9 R8 R7 R6 R5 R4 R3 R2 R1
Sampling 50nsec x x x x x x 0 0 1
Interval 100 x x x x x x 0 0 1
200 x x x x x x 0 1 0
500 x x x x x x 0 1 1
1000 x x x x x x 1 0 0
2000 x x x x x x 1 0 1
5000 x x x x x x 1 1 0
EXTERNAL x x x x x x 1 1 1
------------------------------------------------------------
PRE-TRIG 0 x x x 0 0 0 x x x
SAMPLES 1/8 x x x 0 0 1 x x x
2/8 x x x 0 1 0 x x x
3/8 x x x 0 1 1 x x x
4/8 x x x 1 0 0 x x x
5/8 x x x 1 0 1 x x x
6/8 x x x 1 1 0 x x x
7/8 x x x 1 1 1 x x x
------------------------------------------------------------
RECORD 8192 0 0 0 x x x x x x
LENGTH 4096 0 0 1 x x x x x x
2048 0 1 0 x x x x x x
1024 0 1 1 x x x x x x
512 1 0 0 x x x x x x
256 1 0 1 x x x x x x
128 1 1 0 x x x x x x
64 1 1 1 x x x x x x
(TABLE 2)
Pre-trig samples vs. Record length
Record Length Pre-trig Samples Number of Samples
Digitized before the
Stop trigger
------------ ----------------- --------------------
8192 0 0
1/8 1024
2/8 2048
3/8 3072
4/8 4096
5/8 5120
6/8 6144
7/8 7168
------------------------------------------------------------
4096 0 0
1/8 512
2/8 1024
3/8 1536
4/8 2048
5/8 2560
6/8 3072
7/8 3584
------------------------------------------------------------
2048 0 0
TRANSIAC MODEL 2008 TRANSIENT WAVEFORM RECORDER (DTIZ) Page 12-3
1/8 256
2/8 512
3/8 768
4/8 1024
5/8 1280
6/8 1536
7/8 1792
------------------------------------------------------------
1024 0 0
1/8 128
2/8 256
3/8 384
4/8 512
5/8 640
6/8 768
7/8 896
------------------------------------------------------------
512 0 0
1/8 64
2/8 128
3/8 192
4/8 256
5/8 320
6/8 384
7/8 448
------------------------------------------------------------
256 0 0
1/8 32
2/8 64
3/8 96
4/8 128
5/8 160
6/8 192
7/8 224
------------------------------------------------------------
128 0 0
1/8 0
2/8 32
3/8 32
4/8 64
5/8 64
6/8 96
7/8 96
------------------------------------------------------------
64 0 0
1/8 0
2/8 0
3/8 0
4/8 32
5/8 32
6/8 32
7/8 32
------------------------------------------------------------
o F24 A0: Disable LAM.
TRANSIAC MODEL 2008 TRANSIENT WAVEFORM RECORDER (DTIZ) Page 12-4
o F25 A0: Computer stop trigger.
o F26 A0: Enable LAM and computer readout.
o F27 A0: Enable pedestal measurement. To read,
issue F(25)A(0), wait for posttrigger
samples, and issue an F(2)A(0).
FRONT PANEL INDICATORS AND CONTROLS
LED INDICATORS:
---------------
N - Indicates that the module is being addressed
by the computer.
CVT - Indicates that the module is in the sampling mode.
RECORD - Indicates the total number of samples to be
LENGTH stored (ie: 64-8192). See Table 1.
PRE-TRIGGER - Indicates the number of pre-trigger samples
to be digitizer as a function of the record
length. This can range fro mzero pre-trigger
samples to 7/8 of the record length selected.
(except for a record length of 64 and 128).
See table 1 & 2. The number of pre-trigger
samples is given by:
PRE-TRIGGER SAMPLES=(RECORD LENGTH)*PTS
PTS = 0 to 7/8 depending on the control setting.
SAMPLING - Indicates sampling clock period of 50ns,100ns,
INTERVAL 200ns,500ns,2msec,2msec,5mes or an external
clock. See Table 1.
SWITCH CONTROLS:
---------------
START/STOP - Initiates or stops sampling. START is the same
SAMPLING as the F(9)A(0) command. STOP is the same as
a stop trigger or a F(25)A(0) command and initiates
the post-trigger sampling sequence.
ANALOG CONTROLS:
----------------
OFFSET ADJUST - a multi-turn potentiometer offsets the
input to the ADC to accomodate unipolar and
bipolar signals. See TABLE 3 for different
offset adjust values. The offset adjust
expands approximately a +/- 500 mv. range to
allow for large DC offsets.
(TABLE 3)
Front Panel
Offset Voltage Input Voltage ADC Output
--------------- ------------- ----------
0 -256mv 0
TRANSIAC MODEL 2008 TRANSIENT WAVEFORM RECORDER (DTIZ) Page 12-5
0 128 (BIPOLAR)
+256mv 255
-256 mv 0 0
+256mv 128 (UNIPOLAR +)
+510mv 255
+256 mv 0 255
-256mv 128 (UNIPOLAR -)
-510mv 0
OFFSET - DC signal equal to th eoffset voltage.
VOLTAGE - Measure with a high impedance device (>1Mohm).
SIGNAL INPUTS AND OUTPUTS:
--------------------------
SIGNAL IN - 50 Ohm input impedance; 510 mv. full scale, the
signal input is protected up to a maximum DC
voltage of +/-7V and +/-50V for 1msec ( 10Hz
rep. rate) Extra clamping diode protection
(D10 &D11 on input) can be installed for
signals generated from current source type
outputs (photomultiplier tubes,etc.) and will
give faster recovery times from overload.
Maximum DC current is 20ma.
STOP TRIGGER (IN) - TTL level. 1K Ohm input impedance.
The positive edge triggers the unit to restart the
post-trigger sampling sequence. After receipt of
the first stop trigger all further signals are
ignored until sampling is reinitiated. Protected
against overvoltages of +/-25VDC, +/-250V for 1msec
(10 Hz rate).
EXTERNAL CLOCK - TTL level, 50 Ohm input impedance. The
positive edge initiates the ADC conversion.
Maximum guarenteed frequency is 20Mhz. Minimum
pulse width is 25ns. The external clock frequency
may be varied ("importance sampling") during
the sampling sequence from DC to 20Mhz. The
user must insure glitchless transitions of the
external clock during frequency changes.
CLOCK OUT - TTL signal identical to the sampling clock.
This signal can be used to synchronize multiple
recorders and will drive on 500 Ohm load. (The
50 Ohm external clock input resistors of the driven
modules can be pulled to reduce loading).
Note: this signal is disabled under a F(11)A(0)
or F(27)A(0) command. The delay from external
clock in to clock out is approximately 10-20ns.
DISPLAY OUT - Analog signal which displays the recorded data.
The signal is a bipolar signal +/-2.5V in amplitude.
Zero volts represents half scale (128 binary).
The sweep time is 5Usec./sample. Minimum load
impedance is 1K Ohm. Data is viewable during
TRANSIAC MODEL 2008 TRANSIENT WAVEFORM RECORDER (DTIZ) Page 12-6
sampling however the D/A display driver can only
track low frequency signals (10Khz) at high
sampling rates.
DISPLAY SYNCH - TTL level, into 50 Ohm minimum. The positive
(OUT) edge of this signal is synchronized to the display
of the earliest sample digitized.
o X: X=1 on all commands.
o Q: Q=1 on all valid commands, except where indicated.
o Z: