VXI VT1538A user manual Parameters, Send with VXIplug&play Function hpe14XXcmd

Parameters

Parameter	Parameter	Range of	Default
Name	Type	Values	Units
N_teeth	numeric (int32)	3 to 255	none
index_type	string	MISSing EXTRa	none
ch_list	string	100 - 163	none

Comments • This function can only be linked to the E1538’s first channel. The function works for wheels that have either a missing, or an extra tooth to mark their index position. Figure 14 on page 23 shows a wheel sensed with a variable reluctance sensor (using the VRS input option), but any wheel sensing method is applicable as long as it provides a digital output to the RVEL channel.

•1100, 000 The value read by the algorithm can range from --------------RPS to --------------------

RPS.

nteethnteeth

•As well as sensing rotational velocity, SENS:FUNC:RVEL provides the reference position to the SOUR:FUNC:RPULse function that generates angular positioned pulses. See page 30 for more information on RPULse.

•<n_teeth> is the number of teeth that the wheel would have if it didn’t have missing or extra teeth. For example, we would set <n_teeth> to 12 for the wheel shown in Figure 14 on page 23, even though with the missing tooth, there are only 11.

•<index_type> can be either of the strings "MISSing", or "EXTRa"

•<ch_list> must be the first channel on the SCP, but can contain more than one channel provided that each channel is on a separate E1538. See following note. The related Error Messages are:

3110, "Channel specified is invalid for RVELocity function.

Note Only one channel on any E1538 SCP can be assigned to the SENS:FUNC:RVEL function, and it must be the first channel on the SCP.

•*RST Condition: SENS:FUNC:COND and INP:POL NORM for all digital SCP channels.

•Send with VXIplug&play Function: hpe14XX_cmd(...)

Usage See “Sense Rotational Velocity” on page 22.

SENSE:FUNC:RVEL 12,MISSING,(@140)

12 toothed wheel with one missing, from channel 40

54 Agilent E1538A Enhanced Frequency/Totalize/PWM SCP