Electronic Instrumentation and Measurements AC Power CHAPTER 15

Figure 15.1 Measurement system Figure

Figure 15.2 Devices for the measurement of flow Figure

Figur e 15.3 J thermocouple circuit Figure

Cold junction-compensated thermocouple circuit Figure

Figure 15.5 Effect of connection leads on RTD measurement Figure

Figure 15.6 (a) Four-wire RTD circuit and (b) three-wire Wheatstone bridge RTD circuit Figure

Figure 15.7 Measurement system and types of signal sources Figure

Fi g ur e Ground loop in ground-referenced measurement system Figure

Figure 15.9 Differential (nonreferenced) measurement system Figure

Measuring signals from a floating source: (a) differential input; (b) signal-ended input Figure

Figure Conductive coupling: ground loop and separate ground returns Figure

Figure Capacitive coupling and equivalent-circuit representation Figure

Figure Inductive coupling and equivalent-circuit representation Figure

Shielded Cable Used to Reduce Noise

Figure Discrete op-amp instrumentation amplifier Figure

IC instrumentation amplifier Figure

Figure AD625 instrumentation amplifier Figure

Figure Prototype low-pass filter response Figure

Butterworth low-pass filter frequency response Figure

Figure Chebyshev low-pass filter frequency response Figure

Figure Sallen and Key active filters Figure

Where, Figure 15.22’ Frequency response of the low-pass filter :

Figure Block diagrams of a digital measuring instrument and a digital control system Figure

Figure An n-bit digital-to-analog converter Figure

A 4-bit DAC Figure Figure 15.24’ 15-23

Figure R-2R ladder D/A converter

Figure A digital voltage representation of an analog voltage Figure

Figure Tracking ADC Figure

Integrating ADC Figure

Figure (a) Block diagram of 8-bit successive-approximation ADC; (b) A 3-bit flash ADC Figure

Figure Description of the sample-and-hold process Figure

Sampled data Figure

Figure Data acquisition system Figure

Multiplexed sampled data Figure

Figure Op-amp in open-loop mode Figure

Noninverting op-amp comparator Figure

Figure Input and output of noninverting comparator Figure

Input and output of inverting comparator Figure

Figure Comparator with offset Figure

Waveforms of comparator with offset Figure

Figure Transfer characteristic of zero-crossing comparator Figure

Transfer characteristic of inverting comparator with offset Figure

Figure Comparator response to noisy inputs Figure

Figure Figure 15.48, Transfer characteristic of the Schmitt trigger

Schmitt trigger (general circuit) Figure

Figure Schmitt trigger response to noisy waveforms

Figure 15.51, Schmitt Trigger with Offset

Figure IC monostable multivibrator waveforms

Dual one-shot circuit Figure

Figure NE555 timer

Figure 15.55’

Figure GPIB System with Bus Expander

GPIB(General Purpose Interface Bus) Figure 15.61

Figure 15.61’ Description of GPIB(IEEE 488 Bus) Lines

Figure 15.61’’

Figure IEEE 488 (GPIB) data transmission protocol

Figure Digital data encoded for analog transmission

Modulated digital data for mobile telecommunication CDMA Signal TDMA Signal

EIA232 communication function and connector types for a personal computer and modem. DCE devices are sometimes called "Data Communications Equipment" instead of Data Circuit-terminating Equipment. Figure 15.63’

Figure Communication of a terminal with timesharing computer using MODEM RS232C Communication with ModemRS232C Communication without Modem Format for Asynchronous Serial Data

Figure 15.64’’’

Figure 15.64’ RS-232C signal names and pin numbers

Commonly- used signals Description Transmitted Data (TxD) Data sent from DTE to DCE. Received Data (RxD) Data sent from DCE to DTE. Request To Send (RTS) Asserted (set to 0) by DTE to prepare DCE to receive data. This may require action on the part of the DCE, e.g. transmitting a carrier or reversing the direction of a half- duplex channel. Ready To Receive (RTR) Asserted by DTE to indicate to DCE that DTE is ready to receive data. If in use, this signal appears on the pin that would otherwise be used for Request To Send, and the DCE assumes that RTS is always asserted. Clear To Send (CTS) Asserted by DCE to acknowledge RTS and allow DTE to transmit. This signaling was originally used with half-duplex modems and by slave terminals on multidrop lines: The DTE would raise RTS to indicate that it had data to send, and the modem would raise CTS to indicate that transmission was possible. Description of RS-232 C Commonly-used Signals

Commonly- used signals Description Data Terminal Ready (DTR) Asserted by DTE to indicate that it is ready to be connected. If the DCE is a modem, this may "wake up" the modem, bringing it out of a power saving mode. This behaviour is seen quite often in modern PSTN and GSM modems. When this signal is de-asserted, the modem may return to its standby mode, immediately hanging up any calls in progress. Data Set Ready (DSR) Asserted by DCE to indicate the DCE is powered on and is ready to receive commands or data for transmission from the DTE. For example, if the DCE is a modem, DSR is asserted as soon as the modem is ready to receive dialing or other commands; DSR is not dependent on the connection to the remote DCE (see Data Carrier Detect for that function). If the DCE is not a modem (e.g. a null modem cable or other equipment), this signal should be permanently asserted (set to 0), possibly by a jumper to another signal.null modem Data Carrier Detect (DCD) Asserted by DCE when a connection has been established with remote equipment. Ring Indicator (RI) Asserted by DCE when it detects a ring signal from the telephone line.

Figure 15.64’’

USB (Universal Serial Bus) Figure 15.66

USB 2.0 PCI Controller Figure 15.67

Figure Computer Networks

TCP/IP stack operating on two hosts connected via two routers and the corresponding layers used at each hop Encapsulation of application data descending through the protocol stack. Concept of Internet Protocol Layer

CAN bus line and Frame of CAN message Figure 15.65

Figure 15.65’ Frame format of CAN * Identifier field is composed by 4bits function code and 7 bits node-id by CANopen protocol.

3 bits1 bit2 bits1 bit 2 bytes1 byte4 bytes ccs=1reserved(=0)nesindexsubindexdata Function codeNode IDRTRData lengthData Length4 bits7 bits1 bit4 bits0-8 bytes ccs is the client command specifier of the SDO transfer, this is 0 for SDO segment download, 1 for initiating download, 2 for initiating upload, 3 for SDO segment upload and 4 for aborting an SDO transfer n is the number of bytes in the data part of the message which do not contain data, only valid if e and s are set e, if set, indicates an expedited transfer, i.e. all data exchanged are contained within the message. If this bit is cleared then the message is a segmented transfer where the data does not fit into one message and multiple messages are used. s, if set, indicates that the date set size is specified in n (if e is set) or in the data part of the message index is the object directory index of the data to be accessed subindex is the subindex of the object directory variable data contains the data to be uploaded in the case of an expedited transfer (e is set), or the size of the data to be uploaded (s is set, e is not set) Service Data Object (SDO) protocol Communication objects Process Data Object (PDO) protocol