PAD-T-M: 3574.3259.02/01.00/CI/1/EN
R&S®FS-K5
GSM/EDGE Mobile and Base
Station Test
Software Manual
Software Manual
Test and Measurement
1141.1496.42 – 08
© 2014 Rohde & Schwarz GmbH & Co. KG
Muehldorfstr. 15, 81671 Munich, Germany
Phone: +49 89 41 29 - 0
Fax: +49 89 41 29 12 164
E-mail: info@rohde-schwarz.com
Internet: http://www.rohde-schwarz.com
Subject to change – Data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
Trade names are trademarks of the owners.
The following abbreviations are used throughout this manual:
R&S®FS-K5 is abbreviated as R&S FS-K5
R&S FS-K5 Contents
Software Manual 1141.1496.42 - 08 3
Contents
1 . General Information on Application GSM/EDGE Mobile and Base
Station Tests ....................................................................................... 7
1.1 A brief explanation of GSM (GMSK and EDGE) ........................................................ 7
1.2 Firmware application FS-K5 .....................................................................................10
1.2.1 Installing the FS-K5 firmware application ....................................................................12
1.2.2 Starting the application ................................................................................................12
1.2.3 The application's general settings ...............................................................................14
1.2.4 Measuring with the application ....................................................................................14
1.2.5 Aborting a measurement .............................................................................................14
1.2.6 Results of measurements ............................................................................................15
1.2.7 Exiting the application ..................................................................................................15
1.3 Transducer factors ....................................................................................................16
1.4 Trigger options ...........................................................................................................17
1.4.1 Trigger and time references .........................................................................................18
1.5 Possible errors and difficulties during measurement ...........................................21
1.6 Messages in GSM/EDGE Mode .................................................................................22
2 Measurements with Application Firmware GSM/EDGE Base and
Mobile Station Tests ......................................................................... 24
2.1 The GSM/EDGE Hotkey .............................................................................................25
2.2 Menu Overview ...........................................................................................................26
2.3 Selecting default settings .........................................................................................26
2.3.1 External reference frequency .......................................................................................26
2.3.2 GENERAL SETTINGS menu .......................................................................................27
2.3.3 DEMOD SETTINGS menu ..........................................................................................33
2.3.4 Restoring the limit lines –RESTORE GSM LINES softkey ..........................................39
2.3.5 Setting the transmit channel ........................................................................................40
2.4 Measurement of modulation accuracy of EDGE signals .......................................41
2.4.1 Requirements for the measuring signal .......................................................................41
2.4.2 Quick reference guide ..................................................................................................42
2.4.3 Measurement ...............................................................................................................42
2.4.4 Test hints .....................................................................................................................45
2.4.5 Additional information ..................................................................................................46
2.4.6 Availability of keys and softkeys ..................................................................................47
2.5 Measurement of phase and frequency error ...........................................................48
R&S FS-K5 Contents
Software Manual 1141.1496.42 - 08 4
2.5.1 Requirements for the measuring signal .......................................................................48
2.5.2 Quick reference guide ..................................................................................................48
2.5.3 Measurement ...............................................................................................................49
2.5.4 Test hints .....................................................................................................................51
2.5.5 Additional information ..................................................................................................52
2.5.6 Availability of keys and softkeys ..................................................................................53
2.6 Measurement of carrier power .................................................................................54
2.6.1 Requirements for the measuring signal .......................................................................54
2.6.2 Quick reference guide ..................................................................................................54
2.6.3 Measurement ...............................................................................................................55
2.6.4 Test hints .....................................................................................................................56
2.6.5 Additional information ..................................................................................................59
2.6.6 Availability of keys and softkeys ..................................................................................60
2.7 Measurement of carrier power versus time ............................................................60
2.7.1 Requirements for the measuring signal .......................................................................61
2.7.2 Quick reference guide ..................................................................................................61
2.7.3 Measurement ...............................................................................................................62
2.7.4 Extended Slot Configuration for Multi Slot measurements ..........................................70
2.7.5 Test hints .....................................................................................................................81
2.7.6 Additional information ..................................................................................................84
2.7.8 Availability of keys and softkeys ..................................................................................86
2.8 Measurement of spectrum due to modulation ........................................................87
2.8.1 Requirements for the measuring signal .......................................................................87
2.8.2 Multislot Measurements ...............................................................................................87
2.8.3 Quick reference guide ..................................................................................................89
2.8.4 Measurement ...............................................................................................................89
2.8.5 Test hints .....................................................................................................................95
2.8.6 Additional information ................................................................................................100
2.8.7 Availability of keys and softkeys ................................................................................101
2.9 Measurement of spectrum due to transients ........................................................102
2.9.1 Requirements for the measuring signal .....................................................................102
2.9.2 Quick reference guide ................................................................................................102
2.9.3 Measurement .............................................................................................................103
2.9.4 Test hints ...................................................................................................................109
2.9.5 Additional information ................................................................................................111
2.9.6 Availability of keys and softkeys ................................................................................112
2.10 Measurement of spurious .......................................................................................113
2.10.1 Requirements for the measuring signal .....................................................................113
R&S FS-K5 Contents
Software Manual 1141.1496.42 - 08 5
2.10.2 Quick reference guide ................................................................................................113
2.10.3 Measurement .............................................................................................................113
2.10.4 Test hints ...................................................................................................................114
2.10.5 Additional information ................................................................................................115
2.10.6 Availability of keys and softkeys ................................................................................116
3 Remote Control ............................................................................... 117
3.1 Description of Commands ......................................................................................117
3.1.1 CALCulate:DELTamarker Subsystem .......................................................................117
3.1.2 CALCulate:LIMit Subsystem ......................................................................................118
3.1.3 CALCulate:MARKer Subsystem ................................................................................118
3.1.4 CALCulate:STATistics Subsystem ............................................................................121
3.1.5 CALCulate:UNIT Subsystem .....................................................................................121
3.1.6 CONFigure Subsystem ..............................................................................................121
3.1.7 DISPlay Subsystem ...................................................................................................143
3.1.8 FETCh Subsystem .....................................................................................................143
3.1.9 INSTrument Subsystem .............................................................................................164
3.1.10 READ Subsystem ......................................................................................................166
3.1.11 READ:AUTO - Subsystem .........................................................................................166
3.1.12 SENSe Subsystem ....................................................................................................190
3.1.13 STATus Subsystem ...................................................................................................194
3.1.14 General Trace Commands ........................................................................................196
3.1.15 TRACe:IQ Subsystem ...............................................................................................198
3.1.16 TRIGger Subsystem ..................................................................................................198
3.1.17 UNIT Subsystem ........................................................................................................201
3.2 Table of Softkeys and Hotkeys with IEC/IEEE-Bus Command Assignment......202
3.2.1 Hotkey GSM/EDGE ...................................................................................................202
3.2.2 LINES Key .................................................................................................................207
3.3 Status Reporting Registers for GSM/EDGE Measurements ................................208
3.3.1 Overview of Status Registers ....................................................................................208
3.3.2 STATus:QUEStionable Register ................................................................................209
3.3.3 STATus-QUEStionable:SYNC Register ....................................................................210
4 Index ................................................................................................ 211
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 7
1 General Information on Application
GSM/EDGE Mobile and Base Station Tests
1.1 A brief explanation of GSM (GMSK and EDGE)
The GSM (Global System for Mobile Communication) standard describes the GSM
mobile radio network that is in widespread use today. To enhance this network the
8PSK modulation has been defined in addition to the existing GMSK modulation. With
8PSK the mobile or base station operates in the EDGE (Enhanced Data rates for GSM
Evolution) mode.
This means that GSM includes two different modes: GMSK and EDGE. The term
EDGE is used only wherever there are significant differences between the two modes.
In all other cases, the term GSM will be used.
There are two different standards, distinguished primarily by their frequency bands:
ETSI (for GSM900, GSM1800) and J-STD-007 (PCS 1900 , primarily in the USA).
The physical layer – the layer of the GSM network on which modulation, transmission
of RF signals, reception of RF signals, and demodulation take place – is defined in the
standards
GSM 05.04 Modulation
GSM 05.05 (ETS 300 910) General measurement specifications and limit
values
GSM 11.10 (ETS 300 607-1) Detailed measurement specifications and limit
values for mobiles
GSM 11.21 (ETS 300 609-1) Detailed measurement specifications and limit
values for base stations
J-STD 007 Detailed measurement specifications and limit
values for mobiles and base stations in the 1900
MHz band
As technological development progresses, J-STD 007 is now being integrated into the
other GSM standards.
A T&FDMA method is used to transfer data in the GSM network. This means that the
digital information is transmitted discretely in the time domain as well as in the
frequency domain.
The time domain is divided logically into frames of different length, the smallest unit
being known as a timeslot. A multiframe consists of 26 frames, and a frame has 8
timeslots (see GSM 05.01 for details).
A mobile, therefore, does not communicate continuously with the base station; instead,
it communicates discretely in individual timeslots. In the simplest case, 8 mobiles share
the 8 timeslots of a frame (TDMA - Time Division Multiple Access).
The frequency domain absolute frequency channel number is divided into frequency
bands, and each band, in turn, is subdivided into channels.
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 8
ARFCN 1
Frequency
SLOT FRAME
Power
ARFCN 2
1 FRAME = 8 slots
Time
Mobile 1
Mobile 2
Mobiles transmitting simultaneously on different frequencies: FDMA
SLOT FRAME
Power
Frequency
Time
ARFCN 1
Mobile 1
Mobile 2
SFH = OFF
Mobiles transmitting on the same frequency at different times: TDMA
SLOT FRAME
Power
Frequency
Time
ARFCN 1
Mobile 2: SFH = ON
Mobile 1 transmitting on same frequency, mobile 2 transmitting on different frequencies
ARFCN 2
ARFCN 3
Mobile 1: SFH = OFF
B
T
M
Each frequency channel is identified by its center frequency and a number, known as
the ARFCN, which is a non-band-specific identifier (ARFCN - absolute radio frequency
channel number). A bandwidth of 200 kHz is defined for each frequency channel.
Communication between a mobile and the base station can be either frequencycontinuous or frequency-discrete – distributed across various frequency channels
(FDMA – Frequency Division Multiple Access). In the standards, the abbreviation
"SFH" (slow frequency hopping) is used to designate this mode of communication.
Figure 1-1: Data transmission in GSM network - T&FDMA communication
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 9
935.2MHz 959.8MHz
1 124
925.2MHz 934.8 935 935.2 959.8MHz
975 1023 0 1 124
921.2MHz 934.8 935 935.2 959.8MHz
955 1023 0 1 124
1805.2MHz 1879.8MHz
512 885
1930.2MHz 1989.8MHz
512 810
P-GSM 900
E-GSM 900
R-GSM 900
DCS 1800
PCS 1900
ARFCN
FREQ
ARFCN
FREQ
ARFCN
FREQ
ARFCN
FREQ
ARFCN
FREQ
GSM 450
ARFCN
FREQ
GSM 480
ARFCN
FREQ
GSM 850
ARFCN
FREQ
460.6MHz 467.4MHz
259 293
489MHz 495.8MHz
306 340
867.2MHz 893.8MHz
128 251
GSM 450
ARFCN
FREQ
GSM 480
ARFCN
FREQ
GSM 850
ARFCN
FREQ
450.6MHz 457.4MHz
259 293
479MHz 485.8MHz
306 340
824.2MHz 848.8MHz
128 251
890.2MHz 914.8MHz
1 124
880.2MHz 889.8 890 890.2 914.8MHz
975 1023 0 1 124
876.2MHz 889.8 890 890.2 914.8MHz
955 1023 0 1 124
1710.2MHz 1784.8MHz
512 885
1850.2MHz 1909.8MHz
512 810
P-GSM 900
E-GSM 900
R-GSM 900
DCS 1800
PCS 1900
ARFCN
FREQ
ARFCN
FREQ
ARFCN
FREQ
ARFCN
FREQ
ARFCN
FREQ
Base station and mobile communicate in different frequency ranges. The mobile sends
in the "uplink", and the base station in the "downlink".
The frequencies specified in the standards plus their channel numbers are listed in the
tables below.
Figure 1-2: Downlink – base station transmitting to mobile
Figure1-3 Uplink – mobile transmitting to base station
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 10
In this manual, the functions described are illustrated by means of an FSP.
The characteristics of GMSK modulation:
Phase/frequency error
At this time, two different modes of modulation are used in the GSM mobile radio
network. The original GMSK method has now been joined by an 8PSK method
(EDGE).
The GMSK symbol rate is 1/T = 1625/6 ksymb/s (in other words, approx. 270.833
ksymb/s). This corresponds to 1625/6 kbit/s (in other words approx. 270.833 kbit/s). In
this method, a bit change represents a symbol. The details are laid down in ETSI
standard GSM 05.04.
The 8PSK (EDGE) symbol rate is 1/T = 1625/6 ksymb/s (in other words, approx.
270.833 ksymb/s). This corresponds to 3 x 1625/6 kbit/s (in other words approx. 812.5
kbit/s).
in this method, three bits represent a symbol. The details are laid down in ETSI
standard GSM 05.04.
In both cases, however, the channel bandwidth is restricted to 200 kHz. As these
figures show, the EDGE bit rate is approx. three times higher than that of the GMSK
method.
The customers' demand for higher telecommunication speeds increases the demand
for bandwidth. Therefore the GSM standard has to evolve constantly. An example of
this development is the recently introduced EDGE specification and the GPRS and
HSCSD modes.
Until now, each mobile could use only one timeslot per frame, but the new HSCSD and
GPRS methods will allow permanent assignment of more than one timeslot per mobile,
plus dynamic utilization of multiple timeslots.
The concept behind GPRS (General Packet Radio Service) is dynamic assignment of
up to 8 timeslots to each mobile for data transmission, depending on demand (and
availability in the network).
HSCSD (High Speed Circuit Switched Data) allows permanent assignment of up to 4
timeslots to a mobile.
The two modulation modes GMSK and EDGE can be used.
Of significance for the FS-K5 application firmware in this respect is that the mobile can
send power on a frequency in more than one timeslot.
1.2 Firmware application FS-K5
The characteristics of the GSM system as outlined above have to be measured in
development and production and checked against limit values. The characteristics
belonging to the physical layer that have to be checked include:
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 11
The characteristics of 8PSK modulation:
Phase/frequency error
Carrier power versus time
Power, time characteristic of power, and
timing offset of power within a
timeslot/several timeslots are checked.
The spectral characteristics
The spectral distribution of the energy is
measured in the frequency channel, in
the transmit band and outside the
transmit band.
A distinction is made between two
causes for the form of spectral
distribution:
1. The spectrum caused by GMSK or
8PSK (EDGE) modulation
(measurement is performed only in
that part of the timeslot in which
power is virtually constant, in other
words the switching ramps are
ignored).
2. The spectrum caused by switching
of the power in a timeslot.
Characteristics of GMSK modulation:
PFE Phase/frequency error
Measurement of phase and frequency
error with synchronization to midamble,
IQ offset and IQ imbalance
Characteristics of GMSK modulation:
MAC Modulation Accuracy
Measurement of EVM, of 95:th percentile
value, of origin offset suppression, of
frequency error, of IQ offset and IQ
imbalance with synchronization to
midamble
Carrier power versus time
CPW Carrier power
Measurement of carrier power
PVT Power versus time
Measurement of carrier power versus
time with synchronization to midamble
Spectral characteristics
In accordance with these requirements, the standards define the six measurements
supported in this firmware application.
The GSM/EDGE, FS-K5 application provides a convenient means of performing the
measurements listed below for GSM900 (P-GSM, E-GSM and R-GSM), DCS1800 or
PCS1900 mobiles or base stations (by analogy with the standards GSM 11.10, GSM
11.10-DCS, GSM11.10-1 and J-STD-007 Air Interface):
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 12
MOD Spectrum due to modulation
Measurement of spectrum due to
modulation
TRA Spectrum due to transients
Measurement of spectrum due to
transients
SPU Spurious
Measurement of spurious
Measurements are available for one slot per frame or for the adjustable multislot mode.
Limit values can be defined for each individual measurement. Some basic limit values
are predefined and can be changed or supplemented by other limit values.
The limit lines of GSM and EDGE signals are denoted by the extensions _G or _E,
respectively . Single-slot and multislot limit lines (PVT) are distinguished by means of a
digit appended to the letter _G or _E.
In the PVT, MOD and TRA (only BTS) measurement modes, the limit values depend
on the measured power of the device. An arbitrary midamble can be defined for GMSK
and EDGE (8-PSK). These measurements are preceded by reference measurements
to furnish the correct level setting as required by the standard.
The PFE and PVT measurement modes require a time reference to the midamble
(TSC 0 to 7). The IF signal is digitized, demodulated and processed (IQ mode) for
these measurements.
The sections below contain basic information on the main procedures, settings and
messages of the device. The descriptions of the measurements in Chapter 2 contain
more detailed information specific to the various modes of measurement. The
background information in the sections entitled "Additional information" in Chapter 2 is
supplementary in nature and not necessary for normal operation. This information
merely explains in more detail the internal settings and procedures. Chapter 3
describes the application's remote-control commands. The relevant commands also
accompany each description of a softkey.
1.2.1 Installing the FS-K5 firmware application
When shipped ex works, the FS-K5 firmware application is preinstalled and enabled
and can be used right away.
When shipped separately, the FS-K5 firmware application is accompanied by the latest
version of the instructions for installation and enabling. Notes e.g. on compatibility
between firmware and other applications are provided in the release notes for each
firmware version.
1.2.2 Starting the application
Press the GSM/EDGE hotkey to start the GSM/EDGE, FS-K5 application. The
GSM/EDGE mode is now active, the GSM/EDGE hotkey has a green background.
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 13
GSM/EDGE
Set triggering by switching to the GSM trigger mode (See "Trigger options"); the level
versus time over approx. 9 slots is displayed. No measurement is active.
In order to simplify the procedure for working alternately with the analyzer and
GSM/EDGE modes, the principal parameters are maintained each time you change
from one mode to the other:
Center frequency (CENTER)
Frequency offset (FREQUENCY OFFSET)
Reference level (REF LEVEL)
Reference level offset (REF LEVEL OFFSET)
Attenuation value (RF ATTEN)1
Mode of attenuation (RF ATTEN AUTO/MANUAL)
Attenuation value of electronic attenuator (EL ATTEN)
Electronic attenuator on/off (EL ATTEN OFF)1
Setting of electronic attenuator (EL ATTEN AUTO/MANUAL)
Input impedance (RF INPUT 50 /75 )
Sweep counter (SWEEP COUNT = NO. OF BURSTS)
Trigger (TRIGGER; see "Trigger options")
¹) only with RF ATTEN AUTO: If the GSM/EDGE application is activated, the attenuation is
automatically reduced so that the mixer level is at the maximum ( -10dBm for FSP, -5dBm for
FSU/FSQ). When the GSM/EDGE application is exited, this modification is cancelled (mixer level
maximum -30 dBm for FSP, -25dBm for FSU/FSQ).
Figure 1-4: Start screen in GSM/EDGE mode
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 14
If the display does not update when you activate the GSM/EDGE mode (screen
frozen), check the frequency, reduce external or internal attenuation or increase the
level, or switch to an external trigger.
1.2.3 The application's general settings
The GENERAL SETTINGS menu contains the functions for setting the basic
parameters needed in order to perform measurements.
All the parameters you cannot change in this menu can be controlled by means of the
keys on the basic unit.
You cannot always change all the parameters for specific measurements. Availability is
detailed in the descriptions of the individual measurements.
1.2.4 Measuring with the application
Once you exit the GENERAL SETTINGS menu (PREV or GSM/EDGE), you can start
all measurements by pressing the appropriate softkey in the GSM/EDGE menu.
The PVT, MOD and TRA measurements offer a choice of modes: you can start and
parameterize these modes in the submenu of the measurement you select.
The measurements of the FS-K5 may be divided into 2 classes:
Measurements with and without preceding reference measurements.
The purpose of the reference measurement – depending on the measurement selected
– is to ascertain the current signal level as a reference for the subsequent (main)
measurement.
This applies to all relative measurements (PVT and MOD) that require a reference
value. A warning and the reference level to be set for a correctly adjusted
measurement is issued at the end of the main measurement if the measured signal
level is below a minimum value or above a maximum value.
Reference measurement is not automatic: it must be started manually (START REF
MEAS).
1.2.5 Aborting a measurement
In manual mode you can always abort a measurement in progress.
You can do so either by pressing the softkey with which you start the measurement, or
in a special dialog box where you are prompted for confirmation of your intention.
To start another measurement you always have to abort the measurement in progress.
Aborts take place without further warning.
In remote-control mode the ABORt command can be sent to stop a measurement in
progress (see the manual on IEC/IEEE bus control).
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 15
Measurement
Result
Limit Line
Table
Curve
PFE
Phase error 'peak' and 'RMS';
frequency error in 'Hz'. IQ
offset and IQ imbalance in '%'.
None
None
X
Phase error
MAC
EVM 'Peak' and 'RMS';
Origin Offset Suppression
95:th percentile
frequency error in 'Hz'.
IQ offset and IQ imbalance in
'%'.
None
None
X
EVM per symbol
CPW
PASSED / MARGIN / FAILED
Upper & lower
limit lines
None
X
Carrier power
PVT
PASSED / MARGIN / FAILED
Carrier Power
Time Trig to Sync Start
Upper & lower
limit lines
None
X
Carrier power
MOD
Frequency sweep
PASSED / MARGIN / FAILED
Upper limit line
X
Frequency sweep
MOD
List
PASSED / MARGIN / FAILED
Upper limit line
One level
value and one
limit value per
frequency
value
Compressed
frequency sweep
while
measurement is
in progress
TRA
Frequency sweep
PASSED / MARGIN / FAILED
Upper limit line
X
TRA
List
PASSED / MARGIN / FAILED
Upper limit line
One level
value and one
limit value per
frequency
value
Compressed
frequency sweep
while
measurement is
in progress
SPU
PASSED / MARGIN / FAILED
Upper limit line
X
Frequency sweep
1.2.6 Results of measurements
Figure1-5 Results of measurements
Each measured value is assigned to one of the following quality classes:
PASSED Best quality level; Measured values inside the tolerance window
MARGIN Values inside the limit, but above the tolerance margin (= MARGIN,
user-definable)
FAILED poorest quality level; Values outside limit
Overall assessment of the measurement is shown along with the assessments of the
individual measured values. The worst evaluation is dominant.
1.2.7 Exiting the application
You exit the FS-K5 application by pressing a hotkey to call another operating mode, for
example by pressing the SPECTRUM hotkey to call the ANALYZER mode. The
GSM/EDGE mode is no longer active, the GSM/EDGE hotkey has a grey background,
the newly selected mode is active and its hotkey has a green background.
In order to simplify the procedure for working alternately with the Analyzer and
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 16
GSM/EDGE modes, the principal parameters of the GSM/EDGE measurement active
at the time of the changeover are maintained in the new mode:
Center frequency (CENTER)
Frequency offset (FREQUENCY OFFSET)
Reference level (REF LEVEL)
Reference level offset (REF LEVEL OFFSET)
Attenuation value (RF ATTEN)¹
Mode of attenuation (RF ATTEN AUTO/MANUAL)
Attenuation value of electronic attenuator (EL ATTEN)
Electronic attenuator on/off (EL ATTEN OFF)¹
Setting of electronic attenuator (EL ATTEN AUTO/MANUAL)
Input impedance (RF INPUT 50 /75 )
Sweep counter (SWEEP COUNT = NO. OF BURSTS)
Trigger (TRIGGER; see "Trigger options")
Trigger polarity (POLARITY POS/NEG)
Trigger offset of trigger active in GSM/EDGE (TRIGGER OFFSET)
Resolution bandwidth ² (RBW)
Video bandwidth ² (VBW)
Sweep time ² (SWEEP TIME)
¹) Only with RF ATTEN AUTO: If the GSM/EDGE application is activated, the attenuation is
automatically reduced so that the mixer level is at the maximum (max. –10 dBm for FSP, -5dBm for
FSU/FSQ). When the GSM/EDGE application is exited, this modification is cancelled (mixer level max.
–30 dBm for FSP, -25dBm for FSU/FSQ).
²) For CPW, MOD, TRA and SPU measurements only
These values cannot be transferred exactly in the case of the PFE and PVT measurements.
The values set for PFE and PVT are as follows:
PFE PVT
RBW: 300 kHz 300 kHz
VBW: 1 MHz 3 MHz
SWT: 542.75us 801.25us
1.3 Transducer factors
The FS-K5 provides measurements with transducer factors as described for the basic
unit. The frequency response of external components (power splitters, cables,
attenuator pads) can be corrected or taken into consideration.
Transducer factors can be activated for CPW, MOD, TRA and SPU general and list
measurements. They are set, stored and modified in the SETUP menu using the
TRANSDUCER softkey.
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 17
Trigger setting before the GSM/EDGE mode is
called
GSM trigger
IF power
IF power
RF power (R&S FSP only)
RF power (R&S FSP only)
Extern
External
Other trigger
IF power,
The message: "IF Power Trigger active!" draws your
attention to the change
Measurement
Possible trigger(s)
Trigger used when trigger mode =
Extern
IF Power
RF Power (FSP only
PFE
External / Free Run
External
Free Run / In access
burst mode IF Power
Free Run/ In access
burst mode RF Power
CPW
External / IF Power
External
IF Power
RF Power
PVT
External / Free Run
External
Free Run / In access
burst mode IF Power
Free Run/ In access
burst mode RF Power
MOD
External / IF Power
External
IF Power
RF Power
TRA
Free Run
Free Run
Free Run
Free Run
SPU
Free Run
Free Run
Free Run
Free Run
1.4 Trigger options
For R&S FSP, the measurements in the GSM/EDGE mode can be triggered with the IF
power trigger, the external trigger, or with free run (automatic only, cannot be selected
manually).
If option FSP-B6 is installed, the RF power trigger is available in addition
For R&S FSU/FSQ, the measurements in the GSM/EDGE mode can be triggered with
the IF power trigger, the external trigger, or with free run (automatic only, cannot be
selected manually). The RF power trigger is not available, but its function is provided
almost completely by the FSU/FSQ's IF power trigger.
When the GSM/EDGE mode is called, the trigger changes from the currently active
selection to a GSM trigger mode. This automatically selects a suitable trigger.
Figure 1-6: Trigger options
The IF/RF power and/or external trigger settings are not always possible or useful in all
measurements, so in some cases the FREE RUN trigger is selected automatically. The
table below shows the triggers used for the various measurements and the GSM
trigger mode selected.
Figure 1-7: Trigger settings in GSM trigger mode
The level extern trigger and of the IF and RF Power trigger can be set manually.
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 18
Setting the TRIGGER OFFSET
Limit-value lines
GSM/EDGE
1.4.1 Trigger and time references
The trigger offset for the external trigger and for the IF/RF POWER trigger can be set
automatically or manually. These values are stored in the GSM/EDGE. Each time you
change triggers, the relevant trigger offset value is also set.
The timeslot of the TDMA burst to be measured in the PFE, PVT, MOD and CPW
measuring modes is defined in the ETSI specifications.
In the PFE and PVT measuring modes, correct timing of the timeslot is ensured by
synchronization to the midamble.
In the MOD and CPW measuring modes, the timing of the timeslot has to be set
precisely. The setting can be performed automatically or manually.
The manual setting is performed in the GENERAL SETTINGS menu by adjusting the
trigger offset of the selected trigger until the TDMA burst is positioned inside the mask.
The automatic setting is performed in the GENERAL SETTINGS menu by means of
softkey (AUTO LEVEL & TIME).
Figure 1-8: Trigger setting in GENERAL SETTINGS menu
Two values are computed: trigger offset and GSM/EDGE trigger offset.
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 19
Symbol 1Symbol 0
Trigger (incl. Triggeroffset)
ms
Slottime/2=288,46 ms
Virtual Begin of Slot
17.077
ms
17.077
ms
Virtual End of Slot
Begin first
useful bit
End last
useful bit
Bittransition
13/14
GSM
Triggeroffset
4,125
guard
symbols
57 encrypted symbols
Training
Sequence
S S 57 encrypted symbols
3 tail
symbols
useful duration (part)= 147 symbols = 542,769us
3 tail
symbols
4,125 58 26 4,125583 3
12,375
174 78
12,375
1749 9
8PSK bits
GMSK bits
4,125
guard
symbols
15,231us
214,154us 96us
15,231us
214,154us
11,077us 11,077us
Beginn 'useful part' =
Middle of the first
Tail-Symbol
0
1
0,25 0,5 0,75
Die Zeiten sind auf den ersten Abtastwert eines Symbols bezogen. Dies ist zu
berücksichtigen, da der useful part in der MITTE des 1.Tail-Symbols beginnt!
559,846us
MidMidamble
active part =148 symbols =546,46us
time slot = 156,25 symbols = 576,92us
Trigger
Offset
Slottime=576,92
Trigger to Sync Start
first Sample
of first Midamble Symbol
HW-Trigger
DUT dependent Triggeroffset
Times are referenced to first sampling value of a symbol. This must be taken
into account, because useful part starts at the MIDDLE of the 1st tail symbol
Trigger offset Time between trigger and start of display.
GSM trigger offset Time between trigger and start of slot.
The value of the GSM trigger offset, in other words the time between the trigger and
the start of the slot, is needed for remote control. This time is displayed when you exit
the GENERAL SETTINGS menu or modify the Trigger.
Figure 1-9: Trigger shows the trigger and time references used in the GSM
firmware.
Figure 1-9: Trigger and time references for normal mode
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 20
Symbol 1Symbol 0
Trigger (incl.Triggeroffset)
Virtual Begin of Slot
238,61
ms
Virtual End of Slot
Begin first
useful bit
End last
useful bit
GSM
Triggeroffset
4,125
guard
symbols
Training Sequence
36 encrypted
symbols
8 tail
symbols
useful duration (part)= 87 symbols = 321,23us
3 tail
symbols
4,125 41
36
64,125
8
3
GMSK
bits
64,125 guard symbols
15,231us
151,38us 132,92us
236,77us
29,54us
11,077us
0
1
0,25 0,5 0,75
Die Zeiten sind auf den ersten Abtastwert eines Symbols bezogen. Dies ist zu
berücksichtigen, da der useful part in der MITTE des 1.Tail-Symbols
beginnt!
active part =88 symbols =324,92us
time slot = 156,25 symbols = 576,92us = Slot time
Trigger
Offset
Trigger to Sync Start
first Sample
of first Midamble Symbol
HW-Trigger
DUT dependent Triggeroffset
Times are referenced to first sampling value of a symbol. This must be taken
into account, because useful part starts at the MIDDLE of the 1st tail symbol
17.077
ms
Figure 1-10: Trigger and time references for access burst mode
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 21
Causes:
Wrong working frequency (ARFCN), slow frequency hopping active, test line defective or
wrong attenuation, wrong reference level
Effects:
Reference
measurement:
Inadequate power is measured (e.g. average measurement with
slow frequency hopping), measurement issues warning.
Sweep stops (measurements with midamble synchronization),
warning message: Sync not found
Sweep stops (measurements with IF Power trigger)
Main measurement:
Sweep stops with midamble synchronization active (PFE, PVT)
or IF Power trigger in use. Sweep resumes when signal is
restored.
Remedy:
- Select correct frequency (FREQ ...)
- Deactivate slow frequency hopping (see "Measurements with slow frequency
hopping" in the descriptions of the individual measurements)
- Set correct external attenuation (GENERAL SETTINGS\EXT ATTEN)
- Set correct reference level (GENERAL SETTINGS \REF LEVEL ...)
Effects:
All triggered measurements: sweep stops. This is not immediately apparent on screen.
Remedy:
- Change trigger
- IF/RF Power trigger: reduce level of IF/RF power trigger
reduce external attenuation
increase signal level
Causes:
Power-Trigger used instead of external trigger
TRGS is only available with external trigger
Effects:
During PVT measurement the result display TRGS is not available
Remedy:
Change trigger to Extern
Causes:
Dummy burst, slow frequency hopping active, wrong midamble, wrong modulation type
Effects:
Sweep stops (measurements with midamble synchronization)
Remedy:
Necessary only if measurement does not run, otherwise measurement is possible
- Check the modulation type
- Check the midamble
- Deactivate slow frequency hopping
1.5 Possible errors and difficulties during measurement
The three main sources of error in GSM/EDGE measurement are described below:
No carrier signal
No trigger
Trig. to Sync Start is not available during PVT measurement
Burst not found/Sync not found
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 22
Message
Explanation
- Indicates that list measurement (MOD or TRA) is in
progress
- Abort possible
If this message remains in view and no progress in the trace is
apparent on the screen, measurement might be waiting for a
trigger.
- List measurement aborted by user
- Values obtained during this measurement are ignored
- Reference measurement for PVT or MOD measurement in
progress
- Abort possible
If this message remains in view and no progress in the trace is
apparent on the screen, measurement might be waiting for a
trigger.
- Reference measurement aborted by user
- Values obtained during this measurement are ignored
- When the GSM/EDGE software is activated, this message is
displayed to show that the IF Power trigger has been
activated by default.
See 1.4.1Trigger and time references.
- Indicates that the power measured in reference
measurement does not correspond to the setting for the
reference level (reference level is too high).
Reduce the reference level to approx. the value given in the
message so that the reference level is about 3 dB higher than
the actual power.
- Indicates that the power measured in reference
measurement does not correspond to the setting for the
reference level (reference level is too low).
Increase the reference level to approx. the value given in the
message so that the reference level is about 3 dB higher than
the actual power .
- Indicates that the BURST FIND function is always on in this
version (see DEMOD SETTINGS).
1.6 Messages in GSM/EDGE Mode
All the messages explained below remain on screen only for as long as is absolutely
necessary. They are cleared automatically three seconds after the reason why they
were issued no longer applies. You can close any box with an 'OK button' by pressing
ENTER.
You can continue to use softkeys, keys and hotkeys while a message box is displayed
on screen. If a message box includes an 'ABORT' key, you can abort the action in
progress by pressing ENTER.
R&S FS-K5 General Information on Application GSM/EDGE Mobile and Base Station Tests
Software Manual 1141.1496.42 - 08 23
- Indicates that the SYNC FIND function is always on in this
version (see DEMOD SETTINGS).
- Indicates the current setting for the time between the trigger
(external) and the start of the slot.
See Trigger and time references '
- Indicates the current setting for the time between the trigger
(IF Power) and the start of the slot
See Trigger and time references'
- Indicates that an expected limit line was not found or is
incorrect
Use the RESTORE GSM LIMITS softkey to restore the
original GSM/EDGE limit lines, correct the limit line or switch
on the Limit Checks on TRACE 1.
- Indicates that the automatic level and time offset settings
(AUTO LEVEL & TIME) are completed sucessfully. Values
obtained during this measurement are indicated.
- Indicates that the automatic level and time offset settings
(AUTO LEVEL & TIME) are aborted.
- Indicates that the automatic level and time offset settings
(AUTO LEVEL & TIME) are in progress.
If the measurement stops here, check the trigger and the
trigger levels.
or "Carrier OVERLOAD"
- Indicates that the automatic level and time offset settings
(AUTO LEVEL & TIME) are aborted automatically because
of a missing signal.
- This error may also occur if the level at the instrument is
higher than 27 dBm. In this case, the message "Carrier
Overload" is output.
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Software Manual 1141.1496.42 - 08 24
2 Measurements with Application Firmware
GSM/EDGE Base and Mobile Station
Tests
The following measurements are possible with the R&S FS-K5 application firmware in
single slot or multi slot mode:
PFE Phase-frequency error Measurement of phase and frequency error with
synchronization
to midamble, IQ offset and IQ imbalance
MAC Modulation Accuracy Measurement of EVM, of 95:th percentile value,
origin offset
suppression, of frequency error, of IQ offset and
IQ imbalance
with synchronization to midamble
CPW Carrier power Measurement of carrier power
PVT Power versus time Measurement of carrier power versus time
with synchronization to midamble
MOD Modulation spectrum Measurement of spectrum due to modulation
TRA Transient spectrum Measurement of spectrum due to transients
SPU Spurious Measurement of spurious
Midamble: A standard midamble or an user defined midamble can be selected.
R&S FS-K5 Measurements with Application Firmware GSM/EDGE Base and Mobile Station Tests
Software Manual 1141.1496.42 - 08 25
Analyzer Mode
GSM/EDGESPECTRUM
GSM/EDGE
SPECTRUM
Start the
Application
Exit the
Application
Return to
Main Menu
GSM/EDGE Mode
GSM/EDGESPECTRUM
Key
GSM/EDGE
2.1 The GSM/EDGE Hotkey
Pressing the GSM/EDGE hotkey calls the application. A menu compliant with the
applicable standards is displayed, with a measurement assigned to each softkey. The
GENERAL SETTINGS and DEMOD SETTINGS contain the functions for setting
default values.
There are two situations in which the GSM/EDGE hotkey can be pressed:
1. The GSM/EDGE mode is not active, the GSM/EDGE hotkey has a grey
background:
Pressing the GSM/EDGE hotkey starts the GSM/EDGE application and
opens the main menu of the R&S FS-K5.
At the same time the display changes to Zero Span and the trigger changes
to the GSM trigger.
2. The GSM/EDGE mode is active, the GSM/EDGE hotkey has a green background:
Most of the keys of the device are operational, so you can exit the GSM/EDGE
menu by pressing a key. The GSM/EDGE mode remains active. Press the
GSM/EDGE hotkey to return to the GSM/EDGE main menu.
Pressing the GSM/EDGE hotkey opens the R&S FS-K5 main menu.
The measurements continue. All user-modified parameter settings are
retained.
Figure 2-1: Starting and exiting the application
R&S FS-K5 Measurements with Application Firmware GSM/EDGE Base and Mobile Station Tests
Software Manual 1141.1496.42 - 08 26
2): only available, if option FSP-B6 installed
1): only available for selection DEMOD SETTINGS
MODULATION = 8PSK
AUTO
LEVEL&TIME
GSM/EDGE
PHASE/FREQ
ERROR
CARRIER
POWER
POWER
VS TIME
MODULATION
SPECTRUM
TRANSIENT
SPECTRUM
SPURIOUS
GENERAL
SETTINGS
DEMOD
SETTINGS
TRIGGER
EXTERN
REF LEVEL
EXTERNAL
ATTEN
TRIGGER
IF POWER
NO. OF
BURSTS
TRIGGER
FREE RUN
FREQUENCY
SWEEP
START
LIST
LIST
RESULTS
FREQUENCY
SWEEP
START
LIST
LIST
RESULTS
PAGE
UP
PAGE
DOWN
START
REF MEAS
SELECT
MIDAMBLE
BURST FIND
SYNC FIND
MODULATION
ACCURACY
2)
SET USER
MIDAMBLE
MODULATION
GSM EDGE
RF POWER
TRIGGER
MULTISLOT
AUTO
LEVEL&TIME
1)
POINT/SYMB
4 8
REF MEAS
START
LIMIT
ABS REL
TRIGGER
OFFSE
T
MULTI
CARRIER
BURST FIND
THRESHOLD
OF F
START
REF MEAS
TOP
HIGH RESOL
FULL
RISING
EDGE
FALLING
EDGE
TIME MEAS
HIGH RESOL
FILTER
500K 600K
BURST
FALL/RISE
ZOOM
REF POWER
PEAK RMS
STANDARD -
(DYNAMIC )
EXT CONF
ON OFF
EXT CONF
TABLE
AUTO
LEVEL&TIME
BURST FIND
THRESHOLD
STANDARD -
(DYNAMIC )
EXT CONF
ON OFF
EXT CONF
TABLE
AUTO
LEVEL&TIME
AUTO
LEVEL&TIME
IF/RF PWR
AS IQ TRIG
LIST AVG
LOG LIN
AUTO
LEVEL&TIME
SAP I/Q
ON OFF
2.2 Menu Overview
2.3 Selecting default settings
2.3.1 External reference frequency
Figure 2-2: Overview of menus
Depending on whether or not the mobile station can be set to a service mode or
whether another device (CMD, CMU) "calls" the mobile, it may be necessary to
synchronize the reference frequencies of the devices in use.
This is particularly important before measuring the phase/frequency error or the carrier
power. The procedure for switching to an external reference frequency is the same as
in the basic unit.
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Software Manual 1141.1496.42 - 08 27
REFERENCE
INT EXT
Press the REFERENCE INT / EXT softkey to toggle between the internal and the
external reference sources.
Note:
If you toggle to external reference and the reference signal is not present, the
word "EXREF" is displayed to indicate that synchronization has not been
achieved.
When switching to the internal reference, it is important to ensure that the
external reference signal has been disconnected, in order to avoid undesirable
interaction with the internal reference signal.
Remote: ROSC:SOUR INT
GENERAL
SETTINGS
AUTO
LEVEL&TIME
TRIGGER
EXTERN
REF LEVEL
EXTERNAL
ATTEN
TRIGGER
IF POWER
NO. OF
BURSTS
TRIGGER
FREE RUN
2)
RF POWER
TRIGGER
TRIGGER
OFFSET
IF/RF PWR
AS IQ TRIG
2.3.2 GENERAL SETTINGS menu
GSM/EDGE menu
Pressing the GENERAL SETTINGS softkey opens a submenu for setting the major
parameters of the GSM/EDGE base and mobile station tests application.
When you open this menu the burst mask is displayed, offering graphic support for
setting the reference level and the trigger offset. The burst mask corresponds to the
PVT limit lines. In order for measurement to be correct, the GSM/EDGE signal burst
must be positioned between these lines automatically or manually (see Figure 2-3 and
the descriptions of the REF LEVEL TRIGGER OFFSET and AUTO LEVEL & TIME
softkeys).
This submenu offers the only opportunity of setting the reference level (REF LEVEL)
and the trigger settings for the application with graphic support.
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Software Manual 1141.1496.42 - 08 28
Setting the REF LEVEL
Setting the
TRIGGER OFFSET
Limit lines
GSM/EDGE
REF LEVEL
The REF LEVEL softkey activates the input of the reference level.
You can adjust the reference level graphically by turning the spinwheel so that the
useful part of the burst is between the two horizontal limit lines.
Graphic adjustment takes into account the fact that the reference level must be
approx. 3 dB higher than the power of the mobile station. This is the reason why the
burst mask is 3 dB below the reference level. This protects the analyzer against
overload.
In all other respects the effect of the softkey is the same as that of the REF LEVEL in
the AMPT menu of the spectrum analyzer in the Analyzer mode.
Remote: DISP:TRAC2:Y:RLEV -130dBm to 30dBm
EXTERNAL
ATTEN
The EXTERNAL ATTEN softkey activates the input of external attenuation.
The attenuation is taken into account when the level reading is corrected. All measured
levels and the gradations on the Y axis of the measured-value diagram are shifted by
the selected correction value.
Note:
It is recommended to automatically adjust the reference level and the trigger offset
using softkey AUTO LEVEL & TIME.
The AUTO LEVEL & TIME softkey enables the automatic setting of the reference level
and trigger offset for the active GSM trigger.
The TRIGGER RF POWER softkey is available with option FSP-B6 (TV and RF
trigger) only.
Figure 2-3: Setting trigger offset and reference level with graphic support
R&S FS-K5 Measurements with Application Firmware GSM/EDGE Base and Mobile Station Tests
Software Manual 1141.1496.42 - 08 29
The effect of the softkey is the same as that of entering a level offset with the REF LEVEL
OFFSET softkey in the AMPT menu of the spectrum analyzer in the Analyzer mode.
Remote: DISP:TRAC2:Y:RLEV:OFFS <num_value>value>
AUTO
LEVEL&TIME
The AUTO LEVEL & TIME softkey automatically sets the trigger offset and the
reference level.
If necessary, the IF or RF trigger level and the setting of the mechanical and (if
available) electronic attenuator are optimized in addition.
The following parameters must be correctly set before this auto function is started:
center frequency
GSM trigger mode
modulation mode
multislot settings
midamble
multi carrier
During the AUTO LEVEL & TIME measurement, the signal level is measured and the
reference level is set to 3 dB above the measured signal level. After a successful
measurement, the signal power and the trigger level are indicated.
If the measurement is not successfully completed (termination by the user or as a
result of a "Carrier Overload" error (more than +27 dBm) or "No Carrier" error), the
trigger offset and reference level settings are not changed.
During the AUTO LEVEL & TIME measurement, the attenuation is set to AUTO and
the trigger slope to POSITIVE (for IF-Power trigger only). After the measurement, the
user defined settings are restored.
In the course of the AUTO LEVEL & TIME measurement, the premeasurement for PVT
is performed. It is not necessary to repeat this premeasurement after a successful
AUTO LEVEL & TIME measurement. The premeasurement for MOD, however, has to
be performed separately because it uses a different measurement bandwidth.
If automatic setting is not successful, the settings must be made manually with the
REF LEVEL and TRIGGER OFFSET softkeys.
Remote: READ:AUTO:LEVT?
TRIGGER
OFFSET
The TRIGGER OFFSET softkey activates the manual input of the trigger offset (time
between trigger and start of display).
The trigger offset can be adjusted graphically by turning the spinwheel so that the burst
is within the vertical limit lines (see Figure 2-3).
Note:
It is recommended to automatically adjust the trigger offset and the reference level
using softkey AUTO LEVEL & TIME.
A trigger-offset value is saved for the external GSM trigger and another for the GSM
trigger IF Power. This means:
When GSM-Trigger Extern is active, you can press the TRIGGER OFFSET softkey to
set the offset of the external trigger.
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Software Manual 1141.1496.42 - 08 30
When GSM-Trigger IF Power is active, you can press the TRIGGER OFFSET softkey
to set the offset of the IF Power trigger.
When you change the trigger, the offset belonging to the trigger is activated at the
same time.
When you exit the trigger-offset function, a status window appears showing the GSM
trigger offset (time between trigger and start of slot) needed for remote control. The
time references are described in Chapter 1, "Trigger options".
Note:
The values determined here for the GSM trigger offset must be specified in
remote-control mode for correct synchronization with the
TRIGger[:SEQuence]:SYNChronize:ADJust:EXTernal
TRIGger[:SEQuence]:SYNChronize:ADJust:IFPower or
TRIGger[:SEQuence]:SYNChronize:ADJust RFPower commands
Remote: -- (the GSM trigger offset must be specified
in remote-control mode)
TRIGGER
FREE RUN
The TRIGGER FREE RUN softkey switches on the FREE RUN GSM trigger.
The FREE RUN trigger is very useful in conjunction with R&S FSQ base band inputs if
no external trigger is available and IF power triggering is not possible because of
unbursted signals.
Note:
Please be aware that some triggering is necessary for most of the GSM
measurements. If FREE RUN is used e.g. the CPW measurement does not any
longer deliver useful results. IQ measurements (PVT, PFE & MAC) are working
without a problem because of burst and/or sync search.
Remote: TRIG:SYNC:ADJ:IMM
TRIGGER
EXTERN
The TRIGGER EXTERN softkey switches on the external GSM trigger.
Triggering is either by an external trigger (PFE, CPW, PVT, MOD) or by a free-running
trigger (TRA, SPU), see Chapter 1, "Trigger options".
When the external trigger is used triggering is by a TTL signal at the EXT
TRIGGER/GATE input at the rear of the device.
With this softkey also the external trigger level can be adjusted in the range from 0.5 V
to 3.5 V. The default value is 1.4 V
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