Racal Instruments 2151 User manual

PUBLICATION NUMBER A1571
ISSUE 2.5.95
AND
20 GHz AND 2.6 GHz
VXI COUNTERS
RACAL INSTRUMENTS LTD.
RACAL INSTRUMENTS LTD.
480 Bath Road, Slough, Berkshire SL1 6BE, England.
Telephone: [phone]. Fax: [phone]
RACAL INSTRUMENTS INC.
4Goodyear Street, P.0. Box C-19541, Irvine. CA 92713, USA.
Telephone: [phone]. Fax: [phone]
RACAL SYSTEMS ELECTRONIQUE S.A.
18 Avenue Dutarte, 78150 Le Chesnay, France.
Telephone: [phone]. Fax: [phone]
RACAL SYSTEMS ELETTRONICA srl
Strada 2, Palazzo C4
20090 Miianofiori Assago Milan, Italy.
Telephone: [phone] (auLres.). Fax: [phone]
RACAL ELECTRONIK SYSTEM GmbH
Frankenforster Slrasse 21, 51427 Bergisch Gladbach 1, Germany.
Telephone: [phone]. Fax: [phone] EEX3EB
PUBLICATION DATE: MARCH 1991
Copyright ®1991 by Racai-Dana Instruments Ltd. Printed In England. All rights reserved.
This book or parts thereof may not be reproduced in any form without written permission of the publishers.
»

C€
CE CONFORMITY:
EC Directives 73/23/EEC, 89/336/EEC, 92/31/EEC and 93/68/EEC
Units that carry the CE mark are designed to conform to standards, EN 61010-1, EN
50081-1, EN 50082-1, when used in accordance with these instructions.
SAFETY
Always operate the product in accordance with the instructions in this manual.
EMC
To ensure that EMC integrity is retained always follow good EMC practice. In
particular:
(1) Use good quality coaxial connections for signal input and output leads
(2) Use good quality screened data or control cables and connectors.
(3) Ensure that cable screens are properly terminated within the connectors. Do
not use cables if the terminations are loose or frayed.
(4) Ensure that the screening is continuous through to the chassis of the
equipment.
(5) Ensure that filler panels are fitted to all unused slots in the VXI mainframe.
(6) Note it may be necessary to fit EMI suppression ferrites to one or more of the
connecting leads to ensure compliance of the complete system with EMC regulations.
(7) Ensure that any associated equipment is CE^marked or is of good EMC design
and performance.
(2151)
RACAL Instruments Ltd.

GGSCIB
[A1571 |Microwave Counter :2151

TABLE OF CONTENTS
Paragraph Title Page
SECTION 1TECHNICAL SPECIFICATION... 1-1
SECTION 2GENERAL DESCRIPTION 2-1
1INTRODUCTION 2-1
3MEASUREMENT FUNCTIONS 2-1
3Frequency AFunction 2-1
4Frequency BFunction 2-1
5Frequency CFunction (2151 only) 2-1
6Ratio C/B Function (2151 only) 2-1
7Ratio C/A Function (2151 only) 2-1
8Ratio B/A Function 2-1
9CHECK FUNCTION 2-2
10 SIGNAL INPUT CHANNELS 2-2
13 ADDITIONAL FREQ CACQUISITION MODES (2151 ONLY) .2-3
14 MATHS FUNCTIONS 2-3
15 SPECIAL FUNCTIONS 2-3
16 STORE/RECALL FUNCTIONS 2-3
17 SAMPLE RATE 2-3
18 ERROR INDICATION ’I2-4
19 HOLD FEATURE 2-4
20 RESOLUTION AND GATE TIME 2-4
21 EXTERNAL FREQUENCY STANDARD INPUT 2-4
22 INITIALIZATION 2-4
23 VXI INTERFACE 2-5
SECTION 3
1
3
5
6
7
9
10
PREPARATION FOR USE
UNPACKING
SETTING THE LOGICAL ADDRESS AND INTERRUPT
PRIORITY SWITCHES
INSTALLATION
Connection to the VXI
FREQUENCY STANDARD ...
FUNCTIONAL CHECK
VXI Check
13 CHECK Message Check
14 Data Output Check *
15 SRQ and Status Byte Check ...
16 Input Channel Function Checks
3-1
3-1
3-1
3-1
3-1
3-1
3-5
3-5
3-5
3-6
3-6
3-7
SECTION 4
1
2
3
OPERATION VIA THE VXI
INTRODUCTION
DESCRIPTION OF FRONTPANEL CONNECTORS
AND INDICATORS
DESCRIPTION OF SIDE PANEL SETTING CONTROLS
4-1
4-1
4-1
4-2
2151 OPS Contents 1
A1571/DA

TABLE OF CONTENTS (Contd)
Paragraph
4
5
6
7
7
8
9
11
13
15
17
18
19
20
21
22
24
25
26
27
28
29
31
33
35
36
38
40
41
42
43
47
49
50
52
54
55
61
63
66
68
71
72
76
Contents 2
Title Page
INITIAL SWITCH-ON 4.3
FREQUENCY MEASUREMENT -INPUTA4-3
FREQUENCY MEASUREMENT -INPUT B4-4
FREQUENCY MEASUREMENT -INPUT C(2151 ONLY) 4-4
Normal Automatic Mode ... 4-4
Manual Mode 4.5
Further Functions in FREQ C
(Automatic Mode Only) 4_5
Set LOW FM (FREQ C) 14.5
Set TRACK (FREQ C) 4-6
RATIO MEASUREMENTS C/B (2151 ONLY),
C/A (2151 ONLY) AND B/A 4-6
MEASUREMENT SAMPLE RATE 4-7
Setting and Using the Sample Rate 4-7
Interrogating the Sample Rate 4-7
MULTFUNCTION 4.7
Setting the Multiplier 4.7
Enabling the Multiplier 4-7
Interrogating the Multiplier 4-7
OFFSET FUNCTION 4.3
Setting the Offset 4-8
Enabling the Offset 4-8
Interrogating the Offset 4-8
SMOOTH FUNCTION "* 4.3
CLK10 FREQUENCY STANDARD 4-8
GATE TIME 4.9
SPECIAL FUNCTIONS 4-10
Setting the Special Function Register 4-11
Enabling and Disabling the Special Functions .4-1
1
ERROR CODES ~4_ 12
Clearing the Error Codes 4-12
VXI OPERATING MODES I4-13
READING OUT DATA 4-13
CONTROLLING THE INSTRUMENT 4-13
DATA OUTPUT FORMAT -NORMAL 4-14
DATA OUTPUT FORMAT-.DUMP MODES 4-14
REQUESTING SERVICE 4_18
STATUS BYTE 4.I 8
SETTING THE ENABLE REGISTERS ,4-22
MESSAGE PROTOCOL AND SYNTAX 4-22
System Message Traffic 4-22
Program Messages 4-22
Response Messages 4-23
White Space Character 4-23
OVERLAPPED/SEQUENTIAL COMMANDS 4-23
COMMANDS 4-24
2151 OPS
A1571/DA

TABLE OF CONTENTS (Contd)
LIST OFTABLES
Table Title Page
3.1
3.2
3.3
4.1a
4.1b
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13a
4.13b
4.13c
4.13d
4.14a
4.14b
4.14c
4.14d
4.14e
4.14F
4.14g
4.14b
4.141
4.14j
4.14k
4.141
4.15
4.16
4.17
4.18
4.19
Decimal to Hexadecimal Conversion
Pi VXI Connector Pin Assignment
P2 VXI Connector Pin Assignment
Gate Times for FREQUENCIES Aand B
Gate Times for FREQUENCY C
Major Special Functions
Minor Special Functions
Error Messages
Output Message Format
Function Letters ...
Frequency CDump
Frequency Aand BDump
Associated Registers
Status Byte and Service Request Enable Registers ...
Standard Event Status and Enable Registers
Device Defined Event Status and Enable Registers ...
Common Commands
Common Commands (Continued)
Common Commands (Continued)
Common Commands (Continued)
Device Dependent Commands
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Device Dependent Commands (Continued)
Permitted Terminators
Numerical Input Format
Special Function Request (SF?) Response Format ...
Alphabetic List of Required Command Codes
Alphabetic List of Optional Command Codes
3-2
3-3
3-
4
4-
9
4-9
4-10
4-10
4-12
4-15
4-16
4-17
4-17
4-18
4-19
4-20
4-21
4-24
4-25
4-26
4-27
4-28
4-29
4-30
4-31
4-32
4-33
4-34
4-35
4-36
4-37
4-38
4-39
4-40
4-40
4-41
4-41
4-42
2151 OPS Contents 3
A1571/DA
ALOl/Iss.0 1/03.94

SECTION 1TECHNICAL SPECIFICATION
Model 2151
Technical Specifications
INPUTS
Input A:
Range 10Hz to 100MHz
Sensitivity 20mV rms 10Hz to 80MHz
30mV 80MHz to 100MHz
Input Impedance 1M ohm/35p F
Maximum Input 260V (DC +AC rms) to 2ltHzp
decreasing to 10V rms at 50kHz
and above
Input Attenuation xl and x20, selectable
Filter 50kHz low pass filter selectable
Input B:
Range 40MHz to 1.3 GHz
Sensitivity lOmV (to 1GHz)
75mV (at 1.3GHz)
Input Impedance 50 ohm nominal
Operating Range lOmV to 5V rms
Damage Overload 7V rms (protected by fuse)
VSWR 2.0 :1typical (to 1GHz)
AM Tolerance ^90% (for trough > minimum
pk-pk sensitivity)
Input C:
Range 500MHz to 20GHz
Sensitivity -32dBm (to 12.4GHz)
-27dBm (to 20GHz)
Maximum
Operating Level +7dBm
Damage Level 25dBmpeak
+33dBm with Option 11 high
power limiter
Input Connector PC 3.5 female
Input VSWR <2:1 to 10GHz
<3 :1to 20GHz
AM Tolerance >90% (for trough > minimum
pk-pk sensitivity)
2151 OPS
A1571/DA
ALGl/Iss.01/03.94
FMTolerance
Mode Modulation Rate FMTolerance
Max. Deviation
Automatic
Normal
Low FM
Track
1kHz -10MHz
45Hz -10MHz
300kHz -10MHz
20MHzpk-pk
20MHz pk-pk
20MHz pk-pk
Manual 1kHz -10MHz 60MHz pk-pk
Aquisition Time
Mode Aquisition Time
Automatic
Normal <125mSec
Low FM <1.255mSec
Track <60mSec
Manual <20raSec
Tracking Speed
Mode Tracking Speed
Normal IMHz/Sec
Low FM 80kHz/Sec
Track 1GHz/Sec
Amplitude
Discrimination
(typical) 6dB for signals within 500MHz
20dB for signals at any frequency
Spillback ^-50dBm
(-70dBm if Input Aor Bselected,
or sleep mode)
Input CModes of Operation:
Normal Counter acquires and measures
frequency of the highest level
signal within the sensitivity range
(subject to amplitude
discrimination specifications).
Optimum internal local oscillator
frequency and harmonic number
are determined automatically.
1-1

Low FM For low modulation rates, Low FM
Mode selects an extended
acquisition time
Track For faster measurement and data
output rates, Track Mode selects
the fastest possible acquisition
cycle and tracks the movement of
fast moving input frequencies
Manual For fastest measurement and data
output rates, Manual Mode
suspends automatic operation and
microprocessor calculates
optimum internal local oscillator
frequency and harmonic number
from auser-entered centre
frequency
NB user enters centre frequency
to within +20MHz of input
frequency (±3MHz below 1GHz)
and for full FM tolerance frequency
mustbe entered with ±1 MHz
IF OUTPUT
Available when measurements are made using Input C
in Manual Mode. Available intermittently during
gate time in Auto Mode (due to acquisition cycle).
Frequency Range
Automatic Mode
and Manual Mode 41MHz to 112MHz
Output Level -lOdBm nominal
Output Impedance 50 ohms nominal
Reverse Damage
Level 50V (DC +AC rms) to 210 KHz,
decreasing to 3V rms at
3.5 MHz and above.
MEASUREMENT MODES
Frequency Aand B:
Range Frequency A10Hz to 100MHz
Range Frequency B40MHz to 1.3 GHz
Digits Displayed
(Resolution) 3tolO digits
LSD Displayed (Hz) Fx10 °
(F =frequency rounded up to
next decade, D=no. of digits)
Frequency C:
Range 500MHz to 20GHz
LSD Displayed
(Resolution) 0.1Hz to 1MHz (selectable)
Ratio B/A:
Available as both software and hardware ratio
Range 40MHz to 1.3 GHz
10Hz to 100MHz
LSD Software (Ratio xF0xlO"$D=B))
D=No. of digits, F0=Input B
frequency rounded to next decade
LSD Hardware 6-9 digits 640 xRatio
Fa xGate Time
3-5 digits As above or Ratio x
10(4'D| whichever is
the greater (D =No.
of digits)
Resolution +LSD +1.4 xATrig Error x Ratio
LGate Time _l
Trigger Error =[E. 2+E2]m
.I... IL—
Slew rate at Trigger Point
Ej =Input noise in 100MHz BW
En=Input amplifier noise
Accuracy +Resolution
Ratio C/A, C/B:
Available as software ratio only
Range C/A 500MHz to 20GHz
lOHzto 100MHz
Range C/B 500MHz to 20GHz
Resolution
(Ratio xFcx10' tD+B))
D=No. of digits selected
Fc=Frequency into input C
rounded to next decade
0.1Hz to 1MHz (selectable)
Accuracy (C/A) ±(accuracy of Fc)±accuracy ofF4
^Fa
Accuracy(C/B) ±(accuracy of Fc)±accuracy of FR
F~ F„
1-2 2151 OPS
A1571/DA
ALOl/Iss.0 1/03.94

Math: Standard Output:
Multiply
Offset
Smooth
Used to multiply readings by the
factor held in the Multipiy store Frequency
(user defined number)
Level
Used to automatically offset
readings by the factor held in the
offset store. The factor may be the
current reading or auser defined impedance
number.
10MHz
TTL compatible giving approxi-
mately IV p-p into 50 ohms
90 ohms nominal
Selects arunning average function Maximum reverse
resolution e] et^to^the °S“ aPP'ied l”P“t*15V with n°PeImanent
of the input signal
T1MEBASE SPECIFICATIONS GENERAL SPECIFICATIONS
Internal Standard:
(TCXO) Gate Times
Frequency 10MHz Range
Adjusiment
Range
Aging
±5ppm min.(multiple turn
trimmer)
lppm7year Sample Rate
Temp. Stability ±lppm max. with respect to
frequency at 25DCfrom 0DCto 40DCFront Panel:
External Standard Input: Indicators
Frequency 10MHz
Signal Range
Damage Level
lOOmV rms (sine)tolOVrms (sine)
10V rms (sine) Input/Output
Connectors
Input Impedance lkohm nominal
for signals <IV pk-pk
500 ohm nominal
for signals >10V pk-pk
Coupling AC coupled
VXlbus "CLK10"
Standard A10 MHz system clock is sourced
from the VXlbus slot 0controller,
distributed on connector P2,
differential ECL
Rear Panel
Components
Reference Clock If an external 10MHz reference is
connected via front panel input, it
will automatically override the
internal TCXO reference. This is
the ’’counter reference"
Side Panel
Components
Interface commands enable
selection of reference from
"counter reference" or from
"CLK10" input available on
VXlbus backplane
Check 10MHz displayed
Automatically determined
depending on resolution selected
lmSec to 20Sec (lOSec max. for
channel C)
Rate selectable and the value
displayed
Fail :Red
Active :Amber
Gate ;Green
Power :Green
Achannel input (BNC female)
Bchannel input (BNC female)
Cchannel input precision
connector, PC 3.5 female)
External standard input (BNC
female)
10MHz standard output (BNC
female)
IF output for Channel C(BNC
female)
VXlbus interface sockets Pi and
P2 (96-pin DIN pattern)
Logical address selection switches
interrupt level selection switch
2151 OPS
A1571/DA
AL01/Iss.01/03.94

Power Requirements: OPTIONS
Voltage
Voltage Current
-2VDC OA
+5VDC B40mA
+5V DC (standby) OA
-5.2V DC B25mA
+12V DC 600mA
-12V DC 0A
+24VDC 172mA
-24V DC 0A
Option 11
Power Limiter
Internally fitted to increase Input Cprotection
Max. CW Power 36dBm (4W) to IBGHz
decreasing to 34dBm (2W) at
20GHz
Insertion Loss 3to 4dB depending on frequency
Ordering Information
2151 20GHz VXIbus Microwave Counter
Power Rating <20W
Operating Temp.
Range 0DCto 50°C
Storage Temp.
Range -40°C to +70°C
Safety Designed to meet the requirements
oflEC 348 and follow the guidelines
ofUL 1244
Cooling Requirements:
Air Flow 0.43 litres/sec
Differential Pressure 0.3mm HzO
OPTIONS
11 Input Power Limiter 11-9011
69 1.3 GHz Fuse (pkt 5) 11-1718
93 High Impedance 100MHz probe 23-9104
SUPPLIED ACCESSORIES
Operators Manual
Spare Channel B(1.3GHz) Fuse
This is the recommended working point to give u10°C
maximum rise in temperature for both 2051 and 2151.
VXIbus SPECIFICATIONS
Device type VXIbus message based instrument
Compatibility
Protocol
Output
Module
Fully compatible with VXIbus
System Specification Revision 1.2
for message based instruments
Word Serial, EEEE-STD-48B.2
Engineering format, 12 digits
and exponent
C-size, 2slot wide
262mm (H) x60.7mm (W)
x355mm (D)
Weight 3.0 kg maximum
Logical Address Switch selectable 1to 254
Interrupt Levels Switch selectable 1to 7
1-4 2151 OPS
A1571/DA
ALOl/Iss.0 1/03.94

MODEL2051
Technical Specifications
INPUTS
Input A:
See 2151 Specifications
Input B:
Range 40MHz to 2.6GHz
Sensitivity Better than lOmV
80MHz to 2.6GHz
Operating Range 10mVto 4Vrms
Damage Overload +33dBm lOmV rms
AM Tolerance ^90% (for trough >minimum
pk-pk sensitivity)
(80MHz to 1GHz)
Power Requirements:
Voltage
Voltage Current
-2VDC 0A
+5VDC 840mA
+5V DC (BLondby) 0A
-5.2V DC 735mA
+12V DC 190 mA
-12V DC 0A
+24VDC 0A
-24V DC 0A
Power Rating <11W
Module C-size, 1slot wide
262mm (H) x30-18mm (W)
x355mm (D)
Weight 2.2 kg maximum
All Dther specifications -see 2151 specifications.
Ordering Information
2051 2.6GHz VXIbus Frequency Counter
j
2151 OPS
A1571/DA
ALO1/Is s.01/03 .94
1-5

SECTION 2GENERAL DESCRIPTION
INTRODUCTION
1The Racal Instruments VXIbus microwave counter. Model 2151, is amicroprocessor-
controlled instrument offering high-accuracy measurements with acomprehensive range of
facilities. These facilities include Automatic/Manual Operation, Tracking, Offset, Multiply,
and Store and Recall. All the instrument’s functions are controlled remotely via the VXI
interface.
2The Racal Instruments VXIbus UHF counter, Model 2051, offers high accuracy
measurement over areduced frequency range, with asimilar range of facilities to those
provided on the Model 2151.
MEASUREMENT FUNCTIONS
Frequency AFunction
3The Frequency AFunction is used to measure the frequency of the signal applied to
INPUT A. Aresolution of up to ten digits can be selected with agate time of 1millisecond to
20 seconds depending on the resolution selected.
Frequency BFunction
4The Frequency BFunction is used to measure the frequency of the signal applied to
INPUT B. Aresolution of up to ten digits can be selected with agate time of 1millisecond to
20 seconds depending on the resolution selected.
Frequency CFunction (2151 only)
5The Frequency CFunction is used to measure the frequency of the signal applied to
INPUT C. Aresolution of 0.1 Hz to 1MHz can be selected with agate time of 1millisecond
to 10 seconds depending on the resolution selected and frequency being sampled.
Ratio C/B Function (2151 only)
6The Ratio C/B Function is used to measure the ratio of the frequency applied to INPUT Cto
that applied to INPUT B.
Ratio C/A Function (2151 only)
7The Ratio C/A Function is used to measure the ratio of the frequency applied to INPUT Cto
that applied to INPUT A.
Ratio B/A Function
8The Ratio B/A Function is used to measure the ratio of the frequency applied to INPUT Bto
that applied to INPUT A.
2151 OPS
A1571/DA 2-1

CHECK FUNCTION
9The check function, measures the internal standard frequency to confirm counter operation.
With the CHECK function selected anumber of functional tests of the instrument’s circuits
can be made without the use of additional test equipment (Special Functions 71 to 75).
Although these tests do not check the instrument’s performance to its published
specification, they can be used to verify that the instrument is operating correctly.
SIGNAL INPUT CHANNELS
10 Signal input channels A, Band Care fully independent.
The main characteristics of INPUT Aare as follows:
(1) Frequency range of 10 Hz to 100 MHz;
(2) BNC input connector;
(3) Input impedance of 1MegOhm;
(4) Damage overload of 260 V(DC &AC r.m.s.) to 2kHz, reducing to 10 Vr.m.s. at
50 kHz and above.
(5) 50 kHz Low Pass Filter (selectable).
(6) x20 Attenuator (selectable).
11 The main characteristics of INPUT Bare as follows:
(1) Frequency range of 40 MHz to 1.3 GHz (2151) or 80 MHz to 2.6 GHz (2051);
(2) BNC input connector (Fused) (2 151 only);
(3) Input impedance of 50 Ohms;
(4) Damage overload of +29 dBm protected by the fuse inside the input connector (2151
only).
(5) Overload trip level of4.8 Vr.m.s. (2051 only)
12 The main characteristics of INPUT C(2151 only) are as follows:
(1) Frequency range of 500 MHz to 20 GHz; •*
(2) Input connector -Type APC 3.5;
(3) Input impedance of 50 Ohms;
(4) Damage overload of +25 dBm peak.
2-2 2151 OPS
A1571/DA

ADDITIONAL FREQ CACQUISITION MODES (2151 ONLY)
13 (1) MANUAL -This function is used to override the automatic acquisition cycle of
FREQ C. It enables the user to enter manually acenter frequency and achieve the
fastest possible read rates.
(2) LOW FM -When enabled this function selects an extended acquisition time to
enable frequency readings of signals with low modulation rates. This function is used
only during FREQ Cmeasurements.
(3) TRACK -When enabled this function selects the fastest possible auto-acquisition
cycle to enable swept-frequency readings. This function is used only during FREQ C
measurements.
MATHS FUNCTIONS
14 (1) MULT -When activated this function scales readings by the factor stored in the
'MULT' store.
(2) OFFSET -When activated this function displays the difference between the
measured value and the number held in the ’OFFSET’ store.
(3) SMOOTH -This is aSpecial Function (SF 21). Selecting SMOOTH causes the
counter to take arunning average of the input frequency.
SPECIAL FUNCTIONS
15 This function preselects special functions and enables them.
STORE/RECALL FUNCTIONS
STORE -This function enables the operator to store data in specific stores.
RECALL -This function enables the operator to recall the contents of specific stores.
SAMPLE RATE
SAMPLE -This function is continuously enabled and controls the sample rate.
16 (1)
(2)
2151 OPS
A1571/DA 2-3

ERROR INDICATION
18 Certain errors in the operation ofthe instrument will result in the generation of error codes.
HOLD FEATURE
19 The Hold feature allows readings to be held indefinitely. Anew measurement cycle is
initiated using the MEAS?, *TRG or word serial TRIGGER.
RESOLUTION AND GATE TIME
20 The gate time is determined by the resolution selected. Details of the relationship between
gate time and resolution for each measurement mode are given in Section 4of this manual.
EXTERNAL FREQUENCY STANDARD INPUT
21 The instrument normally uses the internal frequency standard but may be operated using
an external frequency standard- The instrument will operate from the external standard, in
preference to the internal standard (TCXO), whenever the signal at the EXT. STD. INPUT
socket is of sufficient amplitude. It will revert to operation from the internal standard
automatically if the input from the external standard is removed. Selection of the CLK10
frequency standard overrides the internal or external frequency standard, this is supplied to
the instrument via arear edge connector (P2) and is software selectable.
INITIALIZATION
22 When the instrument is first switched on, or when it is initialized under program control, it
will perform the following:
(1) Asoftware and hardware check. Error messages will be generated if afault is found.
(2) The instrument will then set itself to the following state:
FUNCTION STATE
(a) MEASUREMENT MODE FREQ C(2151),
FREQ B(2051)
(b) RESOLUTION 1Hz (2151),
9digits (2051)
(c) MANUAL OFF (Store value: 1GHz)
(2151 only)
2-4 2151 OPS
A1571/DA

(d) SF OFF (Store value: 10, 20,
30, 40, 50,60, 70, 80,90)
(e) MULT OFF (Store value: 1)
(0 OFFSET OFF (Store value: 0)
(B) SAMPLE RATE OPTIMUM (Store value: 0)
(h) LOWFM OFF (2151 only)
(i) TRACK OFF (2151 only)
(k) HOLD OFF (2151 only)
(1) LO Store (for SF41) 340 MHz (2151 only)
(m) HN Store (for SF41) -37 (2151 only)
(n) DUMP Mode OFF
VXI INTERFACE
23 All the instruments functions are controlled via the VXI. The VXI may interface the
instrument to different control media including GPIB, RS232 and Ethernet.
2151 OPS
A1571/DA 2-5

SECTION 3PREPARATION FOR USE
UNPACKING
1Unpack the instrument carefully to avoid unnecessary damage to the factory packing. If it
becomes necessary to return the instrument to Racal Instruments for calibration or repair,
the original packaging should be used. If this is not possible, astrong shipping container
should be used. Ensure that sufficient internal packing is used to prevent movement of the
instrument within the container during transit.
2The MBA link (LK3) is normally set for operation on VXI Revision 1.3 (i.e. link open).
Reposition link (i.e. link closed) for operation on VXI Revision 1.2.
SETTING THE LOGICAL ADDRESS AND INTERRUPT PRIORITY
SWITCHES
3Set the Logical address in the range 1to 254 (decimal) by setting the two switches to the
hexadecimal equivalent. To set the switches use a small flat bladed screwdriver. See
TABLE 3.1 for the decimal to hexadecimal conversion.
4Set the Interrupt Priority in the range 1to 7by setting the switch to the required number,
use asmall flat bladed screwdriver. Do not attempt to set this switch to positions 8, 9and 0.
INSTALLATION
5After setting the Logical Address and Interrupt Priority Switches, install the instrument in
the chassis. Insert the instrument in its slot, ensuring that it is correctly located in the
runners, and push it gently into the chassis until the instrument plugs (PI and P2) connect
with their respective sockets at the rear of the chassis. Lock the instrument in the chassis
by tightening the locking screws at the top and bottom of the instrument front panel.
Ensure that the LACK daisy chain jumpers or switches are open for the appropriate slot (see
chassis instructions).
Connection to the VXI
6Connection to the VXI is made via two 96 pin connectors (Pi and P2) mounted on the rear
edge ofthe instrument board. The pin assignments are given in TABLE 3.2 and TABLE 3.3.
FREQUENCY STANDARD
7Three frequency standards are available for use, these are the instruments own internal
frequency standard, a10 MHz standard connected to the EXT. STD connector or the CLK10
standard. The CLK10 standard is selected under program control. The connection for the
external standard should be made using coaxial cable. Switch on the frequency standard
and the instrument.
2151 OPS
A1571/DA
AL01/Iss.01/03.94
3-1

TABLE 3.1
Decimal to Hexadecimal Conversion
Dec. Hex. Dec Hex. Dec. Hex. Dec. Hex. Dec. Hex. Dec. Hex.
101 44 2C 87 57 130 82 173 AD 216 D8
202 45 2D 88 58 131 83 174 AE 217 D9
303 46 2E 89 59 132 84 175 AF 218 DA
404 47 2F 90 5A 133 85 176 BO 219 DB
505 48 30 91 5B 134 86 177 B1 220 DC
606 49 31 92 5C 135 87 178 B2 221 DD
707 50 32 93 5D 136 88 179 B3 222 DE
808 51 33 94 5E 137 89 180 B4 223 DF
909 52 34 95 5F 138 8A 181 B5 224 EO
10 0A 53 35 96 60 139 8B 182 B6 225 El
11 0B 54 36 97 61 140 8C 183 B7 226 E2
12 oc 55 37 98 62 141 8D 184 B8 227 E3
13 0D 56 38 99 63 142 8E 185 B9 228 E4
14 0E 57 39 100 64 143 8F 186 BA 229 E5
15 OF 58 3A 101 65 144 90 187 BB 230 E6
16 10 59 3B 102 66 145 91 188 BC 231 E7
17 11 60 3C 103 67 146 92 189 BD 232 E8
18 12 61 3D 104 68 147 93 190 BE 233 E9
19 13 62 3E 105 69 148 94 191 BF 234 EA
20 14 63 3F 106 6A 149 95 192 CO 235 EB
21 15 64 40 107 6B 150 96 193 Cl 236 EC
22 16 65 41 108 6C 151 97 194 C2 237 ED
23 17 66 42 109 6D 152 98 195 C3 238 EE
24 18 67 43 110 6E 153 99 196 C4 239 EF
25 19 68 44 111 6F 154 9A 197 C5 240 FO
26 1
A
69 45 112 70 155 9B 198 C6 241 FI
27 IB 70 46 113 71 156 9C 199 C7 242 F2
28 1C 71 47 114 72 157 9D 200 C8 243 F3
29 ID 72 48 115 73 158 9E 201 C9 244 F4
30 IE 73 49 116 74 159 9F 202 CA 245 F5
31 IF 74 4A 117 75 160 A0 203 CB 246 F6
32 20 75 4B 118 76 161 A1 204 CC 247 F7
33 21 76 4C 119 77 162 A2 205 CD 248 F8
34 22 77 4D 120 78 163 A3 206 CE 249 F9
35 23 78 4E 121 79 164 A4 207 CF 250 FA
36 24 79 4F 122 7A 165 A5 208 DO 251 FB
37 25 80 50 123 7B 166 A6 209 D1 252 FC
38 26 81 51 124 7C 167 Jkl 210 D2 253 FD
39 27 82 52 125 7D 168 A8 211 D3 254 FE
40 28 83 53 126 7E 169 A9 212 D4
41 29 84 54 127 7F 170 AA 213 D5
42 2A 85 55 128 80 171 AB 214 D6
43 2B 86 56 129 81 172 AC 215 D7
3-2 2151 OPS
A1571/DA

8A10 MHz signal, derived from the standard in use, is available at the 10 MHz STD
OUTPUT connector on the front panel of the instrument. If this signal is used, the
connection should be made using coaxial cable.
TABLE 3.2
PI VXI Connector Pin Assignment
Pin Row A
Signal
Mnemonic
Row B
Signal
Mnemonic
Row C
Signal
Mnemonic
1D00 BBSY* D08
2D01 BCLR* D09
3D02 ACFAIL* DIO
4D03 BG01N* Dll
5D04 BGOOUT* D12
6D05 BG1IN* D13
7D06 BGIOUT* D14
8D07 BG2IN* D15
9GND BG20UT* GND
10 SYSCLK BG3IN* SYSFAIL*
11 GND BG30UT* BERR*
12 DS1* BR0* SYSRESET*
13 DS0* BR1* LWORD*
14 WRITE* BR2* AM5
15 GND BR3* A23
16 DTACK* AMO A22
17 GND AMI A21
18 AS* AM2 A20
19 GND AM3 A19
20 IACK* GND A18
21 IACK1N* SERCLK A17
22 IACKOUT* SERDAT* A16
23 AM4 GND A15
24 A07 IRQ7* A14
25 A06 IRQ6* A13
26 A05IRQ5* Al 2
27 A04 IRQ4* All
28 A03 IRQ3* A10
29 A02 IRQ2* A09
30 A01 IRQ1 *A08
31 -12V +5V STB
Y
+12V
32 +5V +5V +5V
2151 OPS
Al571/DA 3-3