Section 6 COMMUNICATION SYSTEM AND DEVICES

Question 1

86. Where should the shield be grounded when installing 4-20 mA 2-wire transmitter signal lines?

Answer 1

A. At the transmitter.
B. At the instrument ground bar.
C. At the negative terminal of the power source.
D. At the transmitter and instrument ground bar.

Question 2

87. A new PLC using Ethernet is to be installed. What is configured?

Answer 2

A. The bandwidth.
B. The baud rate.
C. The IP address.
D. The MAC address.

Question 3

88. A Modbus RTU device is unable to communicate with a Modbus ASCII device. What is the cause?

Answer 3

A. The baud rate is too low.
B. The baud rate is too high.
C. They are using different protocols.
D. They have different addresses.

Question 4

89. A pressure transmitter is sending a signal 150 m through shielded twisted pair cable to receiving station. What is the problem if the receiver is not receiving any communication?

Answer 4

A. The cable impedance is too low.
B. The cable shield is grounded at one end.
C. The transmission distance is too great.
D. The transmission distance is too short.

Question 5

90. One end of a Cat 5 network cable using RJ45 connectors has been severed. The severed end is missing. What is the first step of the repair?

Answer 5

A. Solder wire into new connector.
B. Ensure the shield is grounded at one end .
C. Determine if the cable is cross over or straight through.
D. Match wire colours and pin numbers from the non-damaged cable end.

Question 6

91. What is done when a control valve is 150 m from the control room and an I/P is being installed?

Answer 6

A. Locate I/P within 1.0 m of the valve.
B. Locate I/P 30 m from the valve.
C. Locate I/P within 75 m of the valve.
D. Locate I/P in the control room.

Question 7

92. The input signal into a 4-20 mA I/P transducer is 12 mA. The input increases by 10% of span. What is the expected output if the range is 20-100 kPa?

Answer 7

A. 58 kPa
B. 60 kPa
C. 68 kPa
D. 70 kPa

Question 8

93. A turbine flowmeter pulse is fed into a D/A converter. At 50% flow rate, output is only 5% from the D/A. What is the cause?

Answer 8

A. The incorrect pick-up is installed on the turbine.
B. The shield is connected at both ends.
C. The D/A scaling is incorrect.
D. The turbine rotor is missing a blade.

Question 9

94. An I/P is installed on a control valve. During operation with 100% signal, the output is only 9 psi. What is the cause?

Answer 9

A. The output tubing is severed.
B. The supply pressure is too high.
C. The output tubing is blocked completely.
D. The I/P is calibrated for a split range.

Question 10

95. One channel on a hot swappable analog-to-digital converter card has failed. Which procedure is followed to solve the problem and minimize downtime?

Answer 10

A. Notify operations personnel, power down, remove defective card, wear grounded wrist strap, verify card operation, then install new card.
B. Notify operations personnel, wear grounded wrist strap, remove defective card, install new card, then verify card operation.
C. Notify operations personnel, power down, wear grounded wrist strap, remove defective card, install new card, then verify card operation.
D. Notify operations personnel, wear grounded wrist strap, remove defective card, verify card operation, then install new card.

Question 11

96. A signal converter is exhibiting an unstable input signal due to radio frequency interference (RFI) and electromagnetic interference (EMI). Which steps are followed to minimize the instability?

Answer 11

A. __________
B. __________
C. __________
D. __________

Question 12

97. Which parameters are necessary when configuring an Ethernet network gateway?

Answer 12

A. Protocol, parity and stop bit.
B. Subnet mask, protocol and stop bit.
C. Protocol, IP address and baud rate.
D. Subnet mask, IP address and IP range.

Question 13

98. A network with two gateways is experiencing data collisions. The Ethernet cables have been verified using a protocol analyzer. What is the problem?

Answer 13

A. The gateway port speeds do not match.
B. The gateways have the same node address.
C. The gateways are addressed for different networks.
D. The gateways are programmed for different communication protocols.

Question 14

99. An Ethernet to fiber optic converter has stopped communicating. What is done to repair the problem?

Answer 14

A. Replace the power supply.
B. Clean the transmitting bulb.
C. Clean the optical lens.
D. Replace the RS485 cable.