PX409-USB Command Reference

Transcription

1 Page 1 of 5 PX409-USB Command Reference: Note: All commands sent to the PX409-USB series must be terminated by a carriage return or carriage return and linefeed, and is shown in this document as C R and L F. Any parameters shown in square brackets [ ] are optional. Parameters are separated from commands and from each other by a space. Spaces within commands are shown in this document as S P. All commands are case insensitive, meaning any combination of upper/lower case characters are accepted. The USB connection appears on the PC as a virtual serial COM Port. In order to communicate with the PX409-USB, the PC running a terminal program (such as HyperTerminal) must have the following serial communication settings: Baud: 9600 Data Bits: 8 Parity: None Stop Bits: 1 Flow Control: None In addition, the checkboxes in HyperTerminal ASCII Setup, Send line ends with line feeds and Echo typed characters locally should be checked for best appearance. Command Summary: P PA ENQ UNITS DPLACES RANGE Transmit pressure in units specified by the UNITS Command. Transmit pressure in units specified by the UNITS Command, and ambient temperature Degrees Fahrenheit, separated by a comma, and without units. Transmit Unit ID code, firmware version, range, and units. Transmit default units for the device. Transmit the number of decimal places used by the device. Set/Transmit IIR filter period (time constant). Set/Transmit Moving Average filter order. Transmit the pressure range of the device.

2 Page 2 of 5 P Command: Description: - Transmit pressure in units specified by the UNITS Command. Syntax: P C R [ L F] Assuming the pressure at the transducer is PSI, the following is shown on the PC (terminal) screen after typing P and Enter : P PSI C R L F> PA Command: Description: - Transmit pressure in units specified by the UNITS Command, and ambient temperature Degrees Fahrenheit, separated by a comma, and without units. Syntax: PA C R [ L F] This command is only valid for firmware versions and higher. The ambient temperature is always transmitted as 77.0, because there is no temperature sensor on the PCB. This format is for compatibility with TRH Central, which expects a value for ambient. Assuming the pressure at the transducer is PSI, the following is shown on the PC (terminal) screen after typing PA and Enter : PA 45.67, C R L F> ENQ Command: Description: - Transmit Unit ID code, firmware version, pressure range, and units. Syntax: ENQ C R [ L F] The following is typical of what is shown on the PC (terminal) screen after typing ENQ and Enter : USBPX1 C R L F C R L F 0.00 to PSIG C R L F>

3 Page 3 of 5 UNITS Command: Description: - Transmit default units for the PX409-USB. Syntax: UNITS C R [ L F] Assuming units are currently set to PSIG, the following is shown on the PC (terminal) screen after typing UNTIS and Enter : UNITS U = PSIG DPLACES Command: Description: - Transmit the number of decimal places displayed via the comm. port. Syntax: DPLACES C R [ L F] Assuming decimal places are currently set to 2, the following is shown on the PC (terminal) screen after typing DPLACES and Enter : DPLACES DP = 2

4 Command: Description: - Set/Transmit IIR filter period (time constant). Page 4 of 5 Syntax: [ S P PERIOD] C R [ L F] PERIOD (OPTIONAL) Specifies the period to be used by the IIR filter. Valid range of values is 0 to 255. A value of 0 or 1 will disable this filter. The default value is 9. IIR (Infinite Impulse Response) filter is used to filter raw analog to digital converter readings for high frequencies and impulse noise. Assuming the period is currently set to 9, the following is shown on the PC (terminal) screen after typing and Enter : I = 9 The following is shown on the PC (terminal) screen after typing 50 and Enter : I = 50 Command: Description: - Set/Transmit Moving Average filter order. Syntax: [ S P ORDER] C R [ L F] ORDER (OPTIONAL) Specifies the order value to be used by the Moving Average filter. Valid range of values is 0 to 63. A value of 0 will disable this filter. The default value is 4. MA (Moving Average) filter is used to filter pressure values to smooth out low frequency variations in pressure. Assuming the order is currently set to 4, the following is shown on the PC (terminal) screen after typing and Enter : I = 4 The following is shown on the PC (terminal) screen after typing 10 and Enter : I = 10

5 Page 5 of 5 RANGE Command: Description: - Transmit the pressure range of the device. Syntax: RANGE C R [ L F] Assuming the decimal places are currently set to 2, the units are set to PSIA, and the currently set range is 0 to 50, the following is shown on the PC (terminal) screen after typing RANGE and Enter : RANGE R = 0.00 to PSIA