Martel PSC4010 User manual

PSC4010
Reference Manual

PSC4010
Reference Manual
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1.1 Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1.2 Standard Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1.3 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
2. Calibrator Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2.1 Main Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
2.2 Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
2.3 Cursor control / Setpoint control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
3. Using Measure Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.1 Measuring volts, millivolts and frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.2 Measuring mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.3 Measuring mA with Loop Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4. Using Source Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4.1 Setting 0% and 100% Output Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4.2 Using the Automatic Output Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
4.3 Sourcing mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
4.4 Simulating a Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
4.5 Sourcing volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
4.6 Sourcing millivolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
4.7 Sourcing frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
4.8 Sourcing a pulse train . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
5. Remote Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
5.1 Setting up the RS-232 Port for Remote Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
5.2 Changing Between Remote and Local Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
5.3 Using Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
5.4 Remote Commands and Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
5.5 Entering Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
6. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
7. Maintenance / Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
7.1 Replacing Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
7.2 Cleaning the Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
7.3 Service Center Calibration or Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
7.4 Replacement Parts & Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
7.5 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

1
1. Introduction
The Martel PSC4010 Multifunction Process Calibrator is a handheld, battery-operated
instrument that measures and sources electrical and physical parameters. The calibrator has
the following features and functions:
• A graphics display. The display can be used to source and measure volts, current,
frequency, and to source pulse trains.
• Setpoints in each range for quickly increasing/decreasing output
• An interactive menu
• Complete serial interface for remote control
1.1 Customer Service
Corporate Office:
www.martelcorp.com
e-mail: [email protected]
Tel: [phone] Fax: [phone]
Martel Electronics
3 Corporate Park Dr.
Derry, NH 03038
1.2 Standard Equipment
Check to see if your calibrator is complete. It should include:
PSC4010 Calibrator, Instruction Manual, Test Leads, Rubber Boot, NIST Certificate

1.3 Safety information
Symbols Used
The following table lists the International Electrical Symbols. Some or all of these symbols
may be used on the instrument or in this manual.
Symbol Description
AC (Alternating Current)
AC-DC
Battery
CE Complies with European Union Directives
DC
Double Insulated
Electric Shock
Fuse
PE Ground
Hot Surface (Burn Hazard)
Read the User’s Manual (Important Information)
Off
On
Canadian Standards Association
The following definitions apply to the terms “Warning” and “Caution”.
• “Warning” identifies conditions and actions that may pose hazards to the user.
• “Caution” identifies conditions and actions that may damage the instrument being used.
Use the calibrator only as specified in this manual, otherwise injury and damage to the
calibrator may occur.
2

Warning
To avoid possible electric shock or personal injury:
• Do not apply more than the rated voltage. See specifications for supported ranges.
• Follow all equipment safety procedures.
• Never touch the probe to a voltage source when the test leads are plugged into the current
terminals.
• Do not use the calibrator if it is damaged. Before you use the calibrator, inspect the case.
Look for cracks or missing plastic. Pay particular attention to the insulation surrounding the
connectors.
• Select the proper function and range for your measurement.
• Make sure the battery cover is closed and latched before you operate the calibrator.
• Remove test leads from the calibrator before you open the battery door.
• Inspect the test leads for damaged insulation or exposed metal. Check test leads continuity.
Replace damaged test leads before you use the calibrator.
• When using the probes, keep your fingers away from the probe contacts. Keep your fingers
behind the finger guards on the probes.
• Connect the common test lead before you connect the live test lead. When you disconnect
test leads, disconnect the live test lead first.
• Do not use the calibrator if it operates abnormally. Protection may be impaired. When in
doubt, have the calibrator serviced.
• Do not operate the calibrator around explosive gas, vapor, or dust.
• Disconnect test leads before changing to another measure or source function.
• When servicing the calibrator, use only specified replacement parts.
• To avoid false readings, which could lead to possible electric shock or personal injury,
replace the battery as soon as the battery indicator appears.
Caution
To avoid possible damage to calibrator or to equipment under test:
• Use the proper jacks, function, and range for your measurement or sourcing application.
3

2. Calibrator Interface
Figure 1 shows the location of the input and output connections on the calibrator, while Table
1 describes their use.
Table 1: Input and Output Terminals
No. Name Description
1,2 Source/Measure Terminals for sourcing and measuring voltage, frequency,
V, Hz pulse train
3,4 Source/Measure Terminals for sourcing and measuring current
mA terminals
5 Serial port Connects calibrator to a PC for remote control.
4
2
1
5
4
3
F1 F2 F3
CE ENTER
89
4
1
–
5
2
0
6
3
.
7
HOME
Figure 1. Input/Output Terminals

5
Figure 2 shows the location of the keys on the calibrator. Table 2 lists the functions of each
key.
Table 2. Key Functions
No. Name Function
1 Function Keys F1, F2, F3 Used to operate the menu bar at the bottom of the calibrator
display. F1 is used for selecting options in the left box, F2 for
the center box, and F3 for the right box.
2 Home Returns to home menu on the menu bar.
3 Power Turns calibrator on and off.
4 Cursor Control Key Left and right arrow keys are used to select which decade to
be changed in output value. Up and down arrow keys are used
to increase, decrease, or ramp output value.
5 Numeric Keypad Allows user to enter Numeric values.
2.1 Main Display
Figure 3. Display
F1
89
4
1
–
5
2
0
6
3
.
F2 F3
7
CE ENTER
5
3
4
2
1
HOME
Figure 2. Keypad
mA IN -25.00%
MENU
0.000 mA
LIGHT
1
3
4
2

6
The display of the calibrator is shown in Figure 3.
The menu bar is used to setup the display to perform the desired function.
Table 3 explains the different parts of the display:
Table 3: Display Functions
No. Name Description
1 Primary Parameters Determine what parameter is going to be measured or
sourced.
The available options are: VOLTS, FREQ (frequency), PULSE,
mA, mA IN LOOP and mA 2W SIM.
2 Input/Output control Switches between input mode (read), and output mode
(source).
3 Units Shows what unit the measurement or source value is in.
Available options for FREQ and PULSE are CPM, Hz, or KHz
4 Numeric Displays Display the numeric values of the signal being measured, or
sourced. An “OL” reading indicates an out of range or overload
condition.
2.2 Menu Bar
The parameters on the display are controlled by the menu bar, which is located at the bottom
of the LCD. The function keys (F1, F2, and F3) are used to navigate through all the levels and
choices of the menu bar. Refer to the menu tree for a clarification on the layout of all the
levels.
The top level of the menu is the home menu. It can be accessed anytime by pressing the
HOME key. There are three variations of the home menu: the input home menu, the output
home menu, and the pulse home menu.
In the input home menu the only active options are [MENU] and [LIGHT]. The [MENU] option
is used to enter the next level of the menu bar, the main menu. Press the corresponding
function key (F1) to enter the main menu. The [LIGHT] option is used to turn on the LCD
back light. Press the corresponding function key (F2) to turn on the back light.
In the output home menu there are three active options, [MENU], [LIGHT] and [STEP] or
[RAMP]. The first two options work the same as in the input home menu. The third option is
selectable in the Auto Function Menu and is used to turn on and off the selected auto
function. See Section 4.2, Using the Automatic Output Functions. Also leaving this menu or
pressing the Home button will stop the auto functions.

7
The pulse home menu also has three active options, [MENU], [TRIG], and [COUNTS]. The
[TRIG] and [COUNTS] options are used for pulse simulation. The function of these options is
explained in Section 4.2-6 (Sourcing a Pulse).
The next level of the menu bar is the main menu. The levels under the main menu depend on
what mode the calibrator is in.
The main menu has two active options [CONFIG] and [MORE].
Choosing [CONFIG] calls up the parameter selection menu. [MORE] enters the next menu
level.
The Auto Function Menu is the next menu if you are in source mode. Its options are [AUTO
FUNC], [NEXT] and [DONE]. [AUTO FUNC] allows you to adjust the Automatic Output
Function parameters. [NEXT] proceeds to the next menu level and [DONE] returns to the
home menu. See Section 4.2,Using the Automatic Output Functions.
The contrast menu is usually the next menu level. Its options are [CONTRAST], [NEXT], and
[DONE]. The [CONTRAST] option is used to adjust contrast. [NEXT] proceeds to the auto off
main menu, and [DONE] returns to home menu. Contrast is adjusted using the arrow options,
which are available after choosing [CONTRAST].
NOTE: The PSC4010 calibrator offers a wide range contrast adjustment feature to
accommodate operation in extreme temperatures.
In certain cases making large changes in contrast may render the display difficult to read
under normal conditions. If this occurs and the display is too dim or dark to read, proceed
with the following process to set the contrast back to a default setting.
1. Turn on the unit while holding down the “HOME” key.
2. Hold the key down for a count of 10 seconds to restore contrast default settings.
If the display is so dim that you cannot tell if the unit is on or off, use the backlight key to
determine if the power is on or off.
The auto off main menu contains the options [AUTO OFF], [NEXT], and [DONE].
The [AUTO OFF] option is used to turn the automatic shutoff on and off and set the amount of
time the unit needs to stay dormant to shut off. [NEXT] and [DONE] both return to home menu.
When the calibrator is in the frequency or pulse mode, the frequency level menu is added
after the main menu. The options available in this menu are [FREQ LEVEL], [NEXT], and
CONFIG MORE

8
[DONE]. The [FREQ LEVEL] option is used to adjust the amplitude of the wave. [NEXT] is
used to access the contrast main menu, and [DONE] returns to the home menu.
The parameter selection menu is called up when [CONFIG] is selected from the main menu.
It contains the following options: [SELECT], [NEXT], and [DONE]. When the display is
selected, a parameter will start to flash. Use the [SELECT] option to change the parameter,
and the [NEXT] option to switch to another variable. [DONE] returns to the home menu and
enables the selected mode.

9
2.3 Cursor control / Setpoint control
The output value can be controlled by the four cursor control arrows on the keypad. By
pressing one of the arrows a cursor will be added to the display under the last digit of the
output value. The left and right arrow keys are used to select which decade to be changed in
the output value. The up and down arrow keys are used to increase, decrease, or ramp the
output value.
The menu bar will change to the setpoint menu with the touch of any one of the four arrow
keys.
The three function keys are associated with 0, 25, and 100% values, respectively. 0 and 100%
values can be stored by entering a value and then holding down the corresponding function
key. The 25% key will then automatically step through the 25% values.
Figure 4. The Menu Tree
MENU LIGHT
MENU
MENU
MENU
Home Menu
Home Menu
Home Menu
Home Menu
CONFIG
Selection Menu
MORE
SELECT
Parameter Selection
NEXT DONE
FREQ LEVEL
Frequency Level
NEXT DONE
If calibrator is in
Frequency Out
or Pulse mode
CONTRAST
Contrast Menu
NEXT DONE
AUTO OFF
Auto Off Menu
NEXT DONE
LIGHT
LIGHT
LIGHT AUTO FUNC
Auto Function Menu
NEXT DONE
If calibrator is in
Source mode

10
3. Using Measure Modes
3.1 Measuring volts, millivolts and frequency
The calibrator can measure volts or frequency on these jacks. To make the desired
measurements, follow these steps:
1. Select the [CONFIG] option from the main menu.
2. Select the desired parameter for measurement.
3. Connect leads as shown in Figure 5.
Figure 5. Measuring Volts and Frequency with Input/Output Terminals
3.2 Measuring mA
To measure mA follow these steps:
1. Select the [CONFIG] option from the main menu.
2. Choose [mA] from the primary parameters.
3. Make sure the input/output control is set to IN.
4. Connect leads as shown in Figure 6.
Figure 6. Measuring mA with Input/Output Terminals
VOLTS IN
MENU
-0.001 V
LIGHT
MEASURE / SOURCE
3W
mA+ +
V
Hz
–
Ω
4W
mA–
–
+
MEASURE / SOURCE
3W
mA+ +
V
Hz
–
Ω
4W
mA–
–
+
mA IN -25.00%
MENU
0.000 mA
LIGHT

11
3.3 Measuring mA with Loop Power
To test a 2-wire, loop powered transmitter that is disconnected from wiring, use the loop
power function. This function activates a 24V supply in series with the current measuring
circuit. To use this option proceed as follows:
To measure mA with loop power follow these steps:
1. Use the [CONFIG] option from the main menu to select mA IN LOOP.
2. Connect leads as shown in Figure 7.
Figure 7. Connection Using Current Loop
4. Using Source Modes
The calibrator can generate calibrated signals for testing and calibrating process instruments.
It can source voltages, currents, resistances, frequencies and pulses.
4.1 Setting 0% and 100% Output Parameters
To set the 0% and 100% points, use the following steps:
1. Select the [CONFIG] option from the main menu, and choose the desired primary
parameter.
2. Select output [OUT] from the input/output control, and enter the desired value. For
example select [VOLTS OUT].
3. Enter 5V with the keypad and press Enter.
4. Press any one of the four cursor control arrows to display the setpoint control menu.
5. Hold down the Function Key that corresponds to 0% [F1]. 0% will flash and the setpoint is
stored.
6. Repeat these steps, entering 20V and holding the Function Key that corresponds to 100%
[F3].
7. Use the [F2] key to step in either 25% or 10% increments.
4.1-1 Stepping the current output
To use the 25% function with mA output, follow these steps:
1. Select the [CONFIG] option from the main menu, and choose mA.
2. Use the 25% key to cycle between 4 mA and 20 mA in 25 % intervals.
–
+MEASURE / SOURCE
3W
mA+ +
V
Hz
–
Ω
4W
mA–

12
4.2 Using the Automatic Output Functions
There are two automatic output functions, step and ramp. The selected function can be
turned on and off using the Output Home Menu. The Automatic Output Function parameters
can be set in the Auto Function Menu.
Parameters include:
1. Which auto function will be available (Step or Ramp).
2. The Auto Function Time, time between steps for step and time to get from over one limit
to the next for ramp.
3. Step Size, the step size can be set to either 10% or 25%
The limits for the ramp and step functions are set to the 0% and 100% values. See Section
4.1 Setting 0% and 100% Output Parameters. Steps are in either 10% or 25% increments from
the 0% value to the 100% value.
4.3 Sourcing mA
To source a current, follow these steps:
1. Select the [CONFIG] option from the main menu. Choose [mA] from the primary
parameters.
2. Switch to input/output control, and select output [OUT].
3. Connect the leads to the mA terminals, as shown in Figure 8.
4. Enter the desired current using the keypad.
Figure 8. Connections for Sourcing Current
0.000 mA
-25.00 %
mA OUT
MENU LIGHT
–
+
1000 ohms max.
UUT MEASURE / SOURCE
3W
mA+ +
V
Hz
–
Ω
4W
mA–

13
4.3-1 HART™ Resistor Selection
The PSC4010 can be set-up so that the 250 ohm resistor required for Hart™ configuration
devices resides inside the PSC4010. Enabling the PSC4010's internal 250 ohm resistor
eliminates the need to manually add a series resistor during a Hart™ calibration process.
NOTE: When the PSC4010's internal 250 resistor is enabled, maximum load driving
capability drops from 1000 ohms @ 20mA to 750 ohms @20mA.
Enable/Disable Procedure
1. Remove the battery cover and remove the 2 screws that are at the top of the case.
2. Remove the 2 screws on the bottom or lower portion of the case.
3. Gently remove the top half of the case from the bottom.
4. Figure 9. shows the location of the Hart™ jumpers.
Figure 9.
4.4 Simulating a Transmitter
To have the calibrator supply a variable test current to a loop in place of a transmitter, follow
these steps:
1. Select the [CONFIG] option from the main menu.
2. Choose mA simulation from the primary parameters [mA 2W SIM], and enter the desired
current.
3. Connect the 24V loop as shown in Figure 10.
Figure 10. Connections for Simulating a Transmitter
MEASURE / SOURCE
3W
mA+ +
V
Hz
–
Ω
4W
mA–
–
–+
+
LOOP
POWER
SUPPLY
30 VDC
MAX
UUT

14
4.5 Sourcing volts
To source volts follow these steps:
1. Select the [CONFIG] option from the main menu.
2. Choose [VOLTS] from the primary parameters. Switch to input/output control and select
output [OUT].
3. Connect the leads for the voltage source terminals, as shown in Figure 11.
4. Enter the voltage using the keypad.
4.6 Sourcing millivolts
To source volts follow these steps:
1. Select the [CONFIG] option from the main menu.
2. Choose [mV] from the primary parameters. Switch to input/output control and select output
[OUT].
3. Connect the leads for the voltage source terminals, as shown in Figure 11.
4. Enter the millivolts value using the keypad.
Figure 11. Connections for Sourcing Voltage and Frequency
0.00%
mA 2W SIM
MENU
4.000 mA
STEP
LIGHT
–
+
UUT
MEASURE / SOURCE
3W
mA+ +
V
Hz
–
Ω
4W
mA–
VOLTS OUT
MENU
0.000 V
LIGHT STEP

15
4.7 Sourcing frequency
To source a signal use these steps:
1. Select the [CONFIG] option from the main menu and select frequency from the primary
parameters.
2. Select output, and than choose the frequency units.
3. Connect the leads to the frequency output terminals as shown in Figure 12.
4. Enter the desired frequency using the keypad.
5. To change the amplitude, select [FREQ LEVEL] from frequency level menu.
6. Enter the amplitude.
4.8 Sourcing a pulse train
The calibrator can produce a pulse train with an adjustable number of pulses at a desired
frequency. For example, setting the frequency to 60Hz and the number of pulses to 60 would
produce 60 pulses for a period of 1 second. To source a pulse, use the same connection as
for frequency, and proceed as follows:
1. Select the [CONFIG] option from the main menu and select pulse from the primary
parameters.
2. Choose the desired unit and enter the frequency using the keypad.
3. Select the [COUNTS] function from the home menu to enter the number of pulses. Use
[TRIG] to start and stop the signal.
4. The amplitude of the pulse can be adjusted in the same manner as for frequency.
PULSE 5.0 Vpp
MENU
1.0 kHz
TRIG COUNTS
FREQ OUT 5.0 Vpp
MENU
1.0 kHz
LIGHT STEP

16
5. Remote Operation
The calibrator can be remotely controlled using a PC terminal, or by a computer program
running the calibrator in an automated system. It uses an RS-232 serial port connection for
remote operation. With this connection the user can write programs on the PC, with Windows
languages like Visual Basic to operate the calibrator, or use a Windows terminal, such as
Hyper Terminal, to enter single commands. Typical RS-232 remote configurations are shown
in Figure 12.
Figure 12. Calibrator-to-Computer Connection
5.1 Setting up the RS-232 Port for Remote Control
Note: The RS-232 connection cable should not exceed 15m unless the load capacitance
measured at connection points is less than 2500pF.
Serial parameter values:
9600 baud
8 data bits
1 stop bit
no parity
Xon/Xoff
EOL (End of Line) character or CR (Carriage Return) or both
To set up remote operation of the calibrator on the Windows Hyper Terminal, connected to a
COM port on the PC as in Figure 23, use the following procedure:
1. Start Hyper Terminal (located in Accessories/Communications of the Windows Start
menu)
2. Select New Connection.
3. For Name enter PSC4010. Select the serial port that the unit is connected to.
4. Enter the above information for port settings.
5. Select ASCII setup from File/Properties/Settings and mark these choices:
Echo typed characters locally
Wrap lines that exceed terminal width
Optional RS-232 or USB Cable
(See section 7.4)
COM PORT USB PORT
OR
F1 F2 F3
CE ENTER
89
4
1
–
5
2
0
6
3
.
7
HOME

17
6. Select Ok
7. To see if the port works enter *IDN?. This command will return information on the unit.
5.2 Changing Between Remote and Local Operation
There are three modes of operation of the calibrator, Local, Remote, and Remote with
Lockout. Local mode is the default mode. Commands may be entered using the keypad on
the unit or using a computer. In Remote mode the keypad is disabled, and commands may
only be entered using a computer, but choosing [GO TO LOCAL] from the menu on the
calibrator display will restore keypad operation. In Remote with Lockout, the keypad can not
be used at all. To switch modes proceed as follows:
1. To enable Remote mode, type in the serial command REMOTE at the computer terminal.
2. To enable Remote with Lockout, type in REMOTE and LOCKOUT in either order.
3. To switch back to local operation enter LOCAL at the terminal. This command also turns off
LOCKOUT if it was on. For more information on commands refer to the Remote Commands
section.
5.3 Using Commands
5.3-1 Command types
Refer to the Section on Remote Commands for all available commands.
The calibrator may be controlled using commands and queries. All commands may be
entered using upper or lower case. The commands are divided into the following categories:
Calibrator Commands
Only the calibrator uses these commands. For example
MEAS DCV
tells the calibrator to measure voltage.
Common Commands
Standard commands used by most devices. These commands always begin with an "*". For
example
*IDN?
tells the calibrator to return its identification.
Query Commands
Commands that ask for information. They always end with a "?". For example:
FUNC?
Returns the current modes of the calibrator.
Compound Commands
Commands that contain more than one command on one line. For example:
MEAS_DCV;FUNC?
Sets the calibrator to volts measure and queries the function type.

18
Overlapped Commands
Commands that require more time to execute than normal. The command *WAI can be used
after the overlapped command to tell the calibrator to wait until the command finishes before
executing the next command. For example:
TRIG; *WAI
Triggers the pulse train. Once the pulse train has been triggered, the calibrator can proceed
to the next command.
Sequential Commands
Commands that are executed immediately after the are entered. This type includes most of
the commands.
5.3-2 Character Processing
The data entered into the calibrator is processed as follows:
• ASCII characters are discarded if their decimal equivalent is less than 32 (space), except 10
(LF) and 13 (CR):
• Data is taken as 7-bit ASCII
• The most significant data bit is ignored.
• Upper or lower case is acceptable.
5.3-3 Response Data Types
The data returned by the calibrator can be divided into four types:
Integer
For most computers and controllers they are decimal numbers ranging from -32768 to 32768.
For example:
*ESE 140; *ESE? returns 140
Floating
Numbers that have up to 15 significant figures and exponents. For example:
FREQ_LEVEL? returns 5.000000E-00
Character Response Data (CRD)
Data returned as keywords. For example:
FUNC? returns DCV
Indefinite ASCII (IAD)
Any ASCII characters followed by a terminator. For example:
*IDN? returns MARTEL, PSC4010, 250, 1.00