PowerXpert™ Help : Programming Commands for USB Power Sensors : Programming the Sensor
 
Programming the Sensor
Send and Receive Format
Every communication with the power sensor must be suffixed with the line feed (LF) character (ASCII 0x0A). Every response from the sensor is also suffixed with the same character (except when using Microsoft HyperTerminal, which uses a carriage return as the identifier). The sensor rejects any command without the line feed character with a NO TERM response. All commands and responses mentioned in this document are assumed to be suffixed with a new line character. The following considerations must also be observed:
Command arguments presented in this document are enclosed in angle brackets: <argument>. The angle brackets are not included as part of the actual argument.
Floating point numbers are truncated to integers by commands that only use integers as input. For example, if the number of averages is set as 2000.937, the firmware truncates the number to 2000.
For the MA24x08A, MA24x18A, MA24126A and MA243x0A sensors, use only two digits after the decimal in floating point arguments (except FREQ, which uses four digits after the decimal, and gate parameters, which allow three digits after decimal).
HyperTerminal
Only the MA24105A, MA24x08A, MA24x18A, MA24126A and MA243x0A sensors are compatible with Windows HyperTerminal. When programming the sensor with HyperTerminal, the carriage return is used as the termination character instead of a new line. The HyperTerminal port should be configured with a baud rate of 9600 bits per second. To properly format the commands and responses for HyperTerminal, the following check boxes should be checked in Properties | Settings | ASCII Setup:
Send line ends with line feeds
Echo typed characters locally
Append line feeds to incoming line ends
Time Resolution
The maximum time resolution of the sensor is 10 μs, hence all of the time arguments have a 10 μs resolution. This does not apply to the MA24105A sensor.
Sampling Rate
The MA24108A, MA24118A, and MA24126A sensors have two sampling rates. For Continuous Mode and Internal Trigger Source, the sensor has a sampling time of 6.8288 μs or a sampling frequency of 146.438 kHz. External Trigger Source has a sampling time of 7.3347 μs, or a sampling frequency of 136.338 kHz.
The MA242x8A sensors have 1 sample rate for all modes including Continuous Average, Scope, Time Slot, and internal / external trigger modes. The sensor has a sampling time of 7.14 µs or a sampling frequency of 140.056 kHz.
The MA243x0A sensors have 1 sample rate for all modes including Continuous Average, Scope, and internal / external trigger modes. The sensor has a sampling time of 7.14 µs or a sampling frequency of 140.056 kHz.
Error Responses
Any unrecognized command is rejected by the sensor with a BAD CMD message. A valid command coupled with an invalid command is rejected by the sensor with an ERR message. A command failure is also indicated by the sensor with an ERR message.
Default Sensor Settings
The sensor settings in Table: General Default Sensor Settings, MA24105A apply to the MA24105A.
General Default Sensor Settings, MA24105A
Setting
Command
Default Value
Mode of Operation
Continuous Forward Mode
Continuous Reverse Mode
Measurement Frequency
0.35 GHz
Number of Averages
1
Range
Auto range (0)
 
The sensor settings in Table: General Default Sensor Settings, MA24x08A, MA24x18A, MA24126A, MA243x0A, Table: Continuous Average Mode Default Sensor Settings, MA24x08A, MA24x18A, MA24126A, MA243x0A and Table: Time Slot Mode Default Sensor Settings, MA24x08A, MA24x18A, MA24126A apply to the MA24x08A, MA24x18A, MA24126A, MA243x0A.
General Default Sensor Settings, MA24x08A, MA24x18A, MA24126A, MA243x0A
Setting
Command
Default Value
Mode of Operation
Measurement Frequency
0.010 GHz (MA24108A, MA24118A, MA24126A)
2 GHz (MA24208A, MA24218A. MA243x0A)
Averaging Algorithm
Moving (0)
Number of Averages
1
Auto Averaging
Off (0)
Auto Averaging Source
1
Auto Average Resolution
0.01 (2)
Range
Auto range (0)
Step Detect
On (1)
 
Continuous Average Mode Default Sensor Settings, MA24x08A, MA24x18A, MA24126A, MA243x0A
Setting
Command
Default Value
Aperture Time
20 ms
Duty Cycle Correction
100 %
Relative Mode
Off (0)
 
Default buffer command settings (Continuous mode only for MA24x08A, MA24x18A, MA24126A, MA243x0A
Setting
Command
Default Value
Buffer Size continuous mode
8192
Sensor Hold State
0 (RUN)
Enhancement Modulation
OFF
 
Time Slot Mode Default Sensor Settings, MA24x08A, MA24x18A, MA24126A
Setting
Command
Default Value
Number of Slots
8
Slot Width
10 ms
Start Exclusion
0.02 ms
End Exclusion
0.02 ms
 
Scope Mode Default Sensor Settings, MA24x08A, MA24x18A, MA24126A, MA243x0A
Setting
Command
Default Value
Capture Time
20 ms
Number of Points
200
Gate
Disabled (0)
Gate Start
0 ms
Gate End
20 ms
Fence Start
0 ms
Fence End
0 ms
 
Trigger Default Sensor Settings, MA24x08A, MA24x18A, MA24126A, MA243x0A
Setting
Command
Default Value
Trigger Source
Continuous (0)
Trigger Arm Type
Standby (3)
Trigger Level
0 dBm
Trigger Edge
Positive (0)
Trigger Delay
0 ms
Trigger Hold Delay
0 ms
Trigger Noise Parameter
(Only for MA24108A, MA24118A, and MA24126A)
1
Hysteresis (for MA242x8A and MA243x0A)
0 dB