Correlator property summaries

WASP spectrometer properties

Index:

Passband gains
Microcontroller board status
Amplifier modules
Masses
Chassis dimensions
Power supplies
Clocks and oscillators

Timing notes
Synchronization
Board channel numbers
Spectrometer board list
Correlator card rework and test log

Passbands

Passband gain in dB for spectrometer numbers 3, 4, 5, and 6 over a wide bandwidth. .

Passband gain for spectrometer numbers 3, 4, 5, and 6 normalized to 0 dB at peak. The -6 dB points are at 4500 and 7750 MHz.

Microcontroller boards

Spectrometer number	Board serial number	uC code version	Date updated	PLD code version	Date updated
First WASP2	none			n/a	n/a
1		wasp223.16.11.03	5/28/2004	wasp_pld_v3 (3 kHz)	5/28/2004
2		wasp223.16.11.03	5/28/2004	wasp_pld_v3 (3 kHz)	5/28/2004
3		wasp223.28.8.03	8/28/2003	wasp_pld_v3	3/18/2003
Spare	1	wasp223.16.11.03	3/7/2004	wasp_pld_v3 (3 kHz)	3/7/2004
4		wasp223.20.10.03	1/22/2004	wasp_pld_v3 (3 kHz)	3/7/2004
5		wasp223.20.10.03	11/13/2003	wasp_pld_v3 (3 kHz)	3/7/2003
6		wasp223.20.10.03	11/13/2003	wasp_pld_v3 (3 kHz)	3/7/2003

Change record for microcontroller software (txt)

Amplifier modules

Spectrometer number	15 V current	Amplifier module number	Notes
1	762 mA	1	Amplifier wiring together in common channel.
2	837 mA	2	Amplifiers for each branch are wired in series; amplifier wiring from interface board is separate. Problem with short on -5 V supply on assembly. Fixed by loosening interface board screws, tapping, but actual cause is unknown.
3	827 mA	3	Amplifiers have separate wires to interface board, but share common channel for each branch. Gain shapes match well.
4		4	Amplifier wiring on circuit board
5		5	Amplifier wiring on circuit board
6		6	Amplifier wiring on circuit board

Masses

Item	Mass [kg]
Dual downconverter	0.570
Amplifier module and input pads	0.721 typ
uC and clocks board	0.129
Interface card (phsw, thermometry, etc)	0.083
Correlator card	0.119
Correlator card with water cooling hardware	0.356
Total correlator chassis	9.9
Total correlator chassis with water cooling hardware and water	14.0
Power cable, 15'	1
Power supply, linear, single correlator
Power supply, switching, four correlator	10.2

Chassis dimensions

CSO water cooled correlator: 19.75" D, 7" H (without feet), 17.75" W. 1" protrusions from rear panel for water, power.
CSO switching power supply: 19.75" D, 5.25" H (without feet), 17.75" W.
Feet add 0.75" to height, may be removed by removing screws inside bottom cover.

Power supply consumption

Item	+5 V	-5 V	+15 V	Ref
Dual downconverter	8 mA (phsw)	8 mA (phsw)	< 30 mA	IV-116
Amplifier module	< 10 mA	< 10 mA	800 mA typ	IV-116, 124
uC and clocks board	440 mA			II-93
Interface card
Correlator card	580 mA	350 mA		II-93, W2.4

Measured spectrometer power, single-spectrometer supply, 15' cables

Spect	Date	V [V]	I [A]	V [V]	I [A]	V [V]	I [A]	P [W]	Ref
1	3/12/03	5.37	4.56	-5.17	2.54	15.16	0.81	49.9	IV-125
2	3/26/03	5.35	4.48	-5.19	2.55	15.06	0.87	50.3	IV-129

Note: Voltages are higher than nominal to account for voltage drop in power cable; cable dissipation is 2.2 W typ.
The current sense resitor is 0.1 ohm, so a 4.56 A current will appear as a 0.456 V reading at the monitor point.

Measured spectrometer power, four-spectrometer supply, 4' cables

Voltages on front panel monitor meter: +5.67 V, -5.35 V, +15.05 V (Ref: V-68)
Actual voltages in spectrometer chassis: +4.95 V, -4.92 V, +14.71 V (Ref: V-63)

Voltages on front panel monitor meter: +5.64 V, -5.34 V, +15.07 V (Ref: V-92); CSO, ~2 C

Spect	Date	I (+5 V) [A]	I (-5 V) [A]	I (+15 V) [A]	Power [W]	Ref
3	3/21/04	4.40	2.52	0.80	45.9	V-92
4	3/21/04	4.60	2.59	0.84	47.9	V-92
5	3/21/04	4.59	2.56	0.82	47.4	V-92
6	3/21/04	4.54	2.50	0.84	47.1	V-92
Total		18.13	10.17	3.3	188.3

Note: Front-panel monitor voltages are higher than nominal to account for voltage drop in power cables.
The current sense resitor is 0.1 ohm, so a 4.56 A current will appear as a 0.456 V reading at the monitor point.

Clocks and oscillators

Source	Type	Power	Frequency
Microcontroller clock	Crystal	CMOS	16 MHz
ADC clock source	Crystal	CMOS/TTL	2 MHz
Downconverter	DRO	13 dBm (20 mW)	8.00 GHz

Timing notes for wasp_pld_v3, WASP2xx firmware versions, and programming files

The ADC system clock, SCLC, is 2 MHz.
Data read clock from ADCs is 500 kHz.
Internal phase switch frequency is 781.25 Hz (1.28 ms); changed to 3.125 kHz (320 us) 3/7/04. Logic analyzer files below have the slower phase switch.
The basic readout rate is a frame pair, or switched phase switch cycle, at 11.52 ms (86.806 Hz). This corresponds to 9 phase switch cycles per readout, shown in a logic analyzer output for phase switch (pdf).
Logic analyzer output reading out a single 16-lag board, data out onto the daisy-chain line (overview, pdf; zoom to first few bits, pdf; entire logic analyzer file, ala).
Each readout cycle from the ADCs is a half phase switch cycle, 5.76 ms.
Logic analyzer output for the first latch of data from ADCs (pdf) in a new cycle: the 17th rising edge after 16th falling edge at cycle beginning generates a rising latch signal edge. The ADC (see Fig. 6, p. 8 in the DDC101 manual) shifts data out on falling DCLK edge, stable on rising edge. Falling latch edge, 2 us after rising edge, triggers microcontroller read. Subsequent latch signals occur every 20 DCLK cycles (40 us).
ADC acquisition time is K SCLC periods, or 16*0.5 us = 8 us. Allowing for this dead time for acquisition, the integration time efficiency is (5.76 ms - 8 us)/5.76 ms = 0.999. The FDS pulse, which is 40 us, must be shorter than M SCLC periods for continuous readout, or shorter than 64 us.
Logic analyzer output for ADC setup string (pdf). Setup is for unipolar mode, binary output, K = 16, M = 128, L = 1, with parameters in wasp2.h header file.
The Altera PLD programming file for wasp_pld_v3 (pof; 3.125 kHz, right-click and use Save Link Target As ).
The Phytec microcontroller hex file of a recent stable version (wasp2.hex, hex).

Synchronization

WASP2 spectrometers synchronize readouts with hardware signals that run on four parallel-connected lines on the rear-panel 15-pin D connectors (female on chassis). The signals are:

Signal	Pin
Chop	13
Blank	12
NodA	10
NodB	11
Ground	14

One spectrometer or an external generator produces the master signals. The slaves wait for a high level on one of the Nod lines, then a high level on the Chop line, then start integrating when the Blank line is low. The slaves must have a slightly shorter integration time per chop side than the master to allow for synchronization granularity. More details are in the microcontroller software document (ps) and in a breakdown of the code logic (txt).

Board channel numbers

0-15	1-16
16-31	17-32
32-47	33-48
48-63	49-64
64-79	65-80
80-95	81-96
96-111	97-112
112-127	113-128

Spectrometer board list

Spectrometer board list (html)

WASP2 correlator board rework and test log

WASP2 correlator board status and repair histories (txt)