Resumen del contenido incluido en la página 1
VT1538A
ENHANCED FREQUENCY/TOTALIZE/ PWM
SIGNAL CONDITIONING PLUG-ON
USER’S MANUAL
82-0093-000
Release April 28, 2003
VXI Technology, Inc.
2031 Main Street
Irvine, CA 92614-6509
(949) 955-1894
bus
Resumen del contenido incluido en la página 2
VXI Technology, Inc. 2
Resumen del contenido incluido en la página 3
www.vxitech.com INTRODUCTION On May 1, 2003, VXI Technology, Inc. acquired Agilent Technology’s mechanical data acquisition product segment. During the transition period, Agilent branded manuals will be provided with the dynamic and static data acquisition products until the manuals have been rebranded. The following products are provided for in this manner. Dynamic DAC Products VTI Part Number Agilent Part Number Description VT1432A E1432A 16-Channel 51.2 kSamples/s Digitizer Plus
Resumen del contenido incluido en la página 4
VXI Technology, Inc. SUPPORT RESOURCES Support resources for this product are available on the Internet and at VXI Technology customer support centers. VXI Technology World Headquarters VXI Technology, Inc. 2031 Main Street Irvine, CA 92614-6509 Phone: (949) 955-1894 Fax: (949) 955-3041 VXI Technology Cleveland Division VXI Technology, Inc. 7525 Granger Road, Unit 7 Valley View, OH 44125 Phone: (216) 447-8950 Fax: (216) 447-8951 VXI Technology Lake Stevens
Resumen del contenido incluido en la página 5
Agilent 75000 Series C Agilent Technologies E1538A Enhanced Frequency/Totalize/PWM Signal Conditioning Plug-on User’s and SCPI Programming Manual Where to Find it - Online and Printed Information: System installation (hardware/software) ............VXIbus Configuration Guide* Agilent VIC (VXI installation software)* Module configuration and wiring.......................This Manual SCPI programming.............................................This Manual VXIplug&play programming .................
Resumen del contenido incluido en la página 6
Resumen del contenido incluido en la página 7
Agilent E1538A Enhanced Frequency/Totalize/PWM SCP About this Manual This manual describes how to configure the Signal Conditioning Plug-on (SCP) using SCPI commands and explains the capabilities of this SCP. The contents of this manual are: • Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 4 • Identifying the Plug-on (IMPORTANT). . . . . . . . . . . . . . . page 5 • Setting Configuration Switches . . . . . . . . . . . . . . . . . . . . . page 6 • Ins
Resumen del contenido incluido en la página 8
Introduction The Agilent E1538A provides eight TTL compatible channels of digital I/O. Channels can be individually configured to perform any one of the following functions: • Input: -- Static digital state -- Frequency measurement -- Period meaurement -- Totalize positive or negative signal transitions -- Pulse width measurement -- Rotational velocity (senses added or missing cogwheel teeth) -- Quadrature position. (requires 2 channels) • Output (configurable as Open Drain or passive pull-up)
Resumen del contenido incluido en la página 9
both full and half step modes.(requires 2 or 4 channels) The logical sense of input and output channels can be configured as inverted or normal. Input-configured channels have individually programmable threshold levels that can range from -46V to +46V. Identifying the Plug-on (IMPORTANT) There are two versions of the E1538A. The early version does not support a PERiod measurement command set. Early versions have ROM revision February 1998 and earlier. The later version adds period measuremen
Resumen del contenido incluido en la página 10
Setting Configuration Switches The SCP has three packages of eight switches each. The package labeled OE (Output Enable) determines a channel’s I/O direction. The package labeled PU (pull-up) controls whether or not a channel is floating or pulled up to an internal 5V supply. The package labeled VRS (for channels 0 and 1 only) can enable special input signal conditioning compatible with variable reluctance sensors. For a discussion on using the VRS mode, see "VRS Mode Input Operation" on p
Resumen del contenido incluido en la página 11
Installation Installation for this Plug-on is identical to other SCPs and is covered in Chapter 1 of your Agilent E1415 or E1419 User’s Manual. Connecting To The Terminal Module The SCP connections for the Terminal Modules are shown on the self-adhesive labels that come with the SCP. Use these to label terminal definitions on your terminal module. The connections are shown in Figure 3. Figure 3. E1538A Terminal Module Connections Figure 4 shows the screw terminal Option 11 for the E1419A. Ag
Resumen del contenido incluido en la página 12
Figure 4. E1419A Option 11 Terminal Module Connections Recommended Signal Connections Figure 5 shows the recommended method of wiring digital I/O channels, as well as the maximum voltage limitations for the E1538A. Figure 5 shows the shields connected directly to the E1415 ground. This is to limit potential noise on the digital wiring from affecting low-level analog channel wiring within the Terminal Module. Note The G (analog guard) terminals are connected through 10K Ohm resistors to chass
Resumen del contenido incluido en la página 13
Figure 5. Recommended Connections and Voltage Limits Input and Output Characteristics This section describes the E1538’s channel input and output electrical characteristics. Refer to Figure 6 for the following discussions. Input Characteristics When configured for input, E1538 channels provide digital input through the threshold comparator. The digital input threshold level is programmable with a SCPI command from -48 to +47.625 VDC in .375V steps (relative to the Lnn terminal). The threshol
Resumen del contenido incluido en la página 14
is to maintain a constant-level digital output while the input varies from millivolts to several tens of volts. For simple sensing of switches and open collector logic devices, a channel’s pull-up resistor can be connected by closing its PU switch. Figure 6. The E1538A Input/Output Characteristics VRS Mode When the VRS configuration switch is set to on, the input signal conditioning for that channel is changed to make it compatible with a typical variable Input Operation (SCP reluctance sens
Resumen del contenido incluido en la página 15
() V – 17.5 sensor formula R = -- --- -- -- -- -- -- -- -- --- -- -- -- -- -- -- -- -- - to calculate the protection resistor’s value. external 0.0032 Figure 7 shows the VRS mode input characteristics. Figure 7. VRS Mode Input Characteristics Output Characteristics The output stage of the E1538A is simply a MOS FET transistor that is configured as "open-drain" when the pull-up resistor is not connected (PU switch is OFF). For simple interfacing to logic devices, the pull-up resistor can be c
Resumen del contenido incluido en la página 16
Checking the ID To verify the SCP type(s) installed on your VXI module, use the SYSTem:CTYPe? (@) command. of the SCP • 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
Resumen del contenido incluido en la página 17
• Channels in must be input configured channels Determining the Input To determine a channel’s input threshold level, use the command: INPut:THReshold:LEVel? (@) Threshold Level Note Because the E1538 rounds to the nearest multiple of 0.375, the returned value can be different from the value sent. • must specify a single input-configured channel. • INP:THR:LEV? returns a numeric value between -46 and +46. The C-SCPI type is int32. To query the threshold le
Resumen del contenido incluido en la página 18
Reading Static This means reading a channel’s current digital state when an algorithm executes. This is the default function assigned to all digital input channels Digital State after *RST and at power-up. To set individual channels to this function use the SCPI command [SENSe:]FUNCtion:CONDition (@). The value returned to an algorithm is a floating point representation of 0 or 1, depending on the state of the input signal and the channel’s INP:POL setting. To set channels 40 throug
Resumen del contenido incluido en la página 19
Totalize Positive or Use [SENSe:]FUNCtion:TOTalize (@) to configure channels to totalize. Totalize means to simply count state transitions (either positive Negative Edge State going, or negative going). Figure 9 A shows totalizing transitions between Changes each algorithm execution. Figure 9 B shows totalizing all transitions starting from the time the module last received an INITiate command. Use [SENSe:]TOTalize:RESet:MODe INIT | TRIG,(@) to configure the totalize chann
Resumen del contenido incluido en la página 20
About Period and The E1538A actually measures signal period for both the period and frequency functions. If the measurement function is set to frequency rather Frequency than period, the SCP returns the reciprocal of the measured period. The Measurements resolution of each period measurement is based on the time processor chip’s timer period (238.4nS). To improve resolution on faster input signals, multiple signal periods can be measured and averaged. For period measurements there are two
