VXI VT1538A Checking the ID of the SCP, Configuring the Channels, Programming Input Channels

Checking the ID of the SCP

To verify the SCP type(s) installed on your VXI module, use the SYSTem:CTYPe? (@<channel>) command.

•The channel parameter specifies a single channel in the channel range covered by the SCP of interest. The first channel number for each of the eight SCP positions are; 0,8,16,24,32,40,48, and 56.

The value returned for the E1538A SCP is:

HEWLETT-PACKARD,E1538A Enhanced Frequency/Totalize/PWM SCP,0,0

To determine the type of SCP installed on channels 0 through 7 send

SYST:CTYPE? (@100)	query SCP type @ ch 0
enter statement here	enter response string

Configuring the Channels

The E1538A has eight digital channels. The Power-on and *RST state is that all input-configured channels sense static digital state (SENS:FUNC:COND), and all output-configured channels output static digital state (SOUR:FUNC:COND). Logical sense is normal

(INP:POL NORM and OUTP:POL NORM).

Configuring I/O Direction

Programming Input Channels

Setting the Input

Threshold Level

Channels are configured for input or output with the I/O direction switches (see "Setting Configuration Switches" on page 6).

This section deals with all aspects of programming input channel functions. Channels are configured for input with the I/O direction switches (see "Configuring Input-Output direction" on page 6). A related error message: 3123,"E1538 OE switch ON conflicts with this command."

The E1538 allows programmatically setting the input threshold level for each input configured channel. The input threshold can be set from -46VDC to +46VDC with .375V resolution. While input polarity is set to NORMAL, an input level higher than the threshold level is considered a logic one, and an input level lower than the threshold level is considered a logic zero. If input polarity is set to INVerted, an input level higher than the threshold level is considered a logic zero and an input level lower than the threshold level is considered a logic one. To set input threshold level use the command

INPut:THReshold:LEVel <level>,(@<ch_list>)

•<level> is a value between -46 and +46 inclusive. The resolution for <level> is 0.375 Volts. The *RST and power-on default for <level> is 1.78 volts.

Note The value sent for <level> will be rounded to the nearest multiple of 0.375 Volts. For instance, 5 would be 4.875, 10 would be 10.125, 9.5 would be 9.375, and 15 would be 15. The INP:THR:LEV? query will return the actual setting.

12 Agilent E1538A Enhanced Frequency/Totalize/PWM SCP