Revisions: IC660EBA104A , IC660EBA104B , IC660EBA104C , IC660EBA104D , IC660EBA104E , IC660EBA104F , IC660EBA104G , IC660EBA104H , IC660EBA104I , IC660EBA104J , IC660EBA104K , IC660EBA104L , IC660EBA104M , IC660EBA104N , IC660EBA104O , IC660EBA104P , IC660EBA104Q , IC660EBA104R , IC660EBA104S , IC660EBA104T , IC660EBA104U , IC660EBA104V , IC660EBA104W , IC660EBA104X , IC660EBA104Y , IC660EBA104Z ,
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Current source Input/Output Blocks have 4 input and 2 output circuits for 4 20mA devices. Two Current source Analog Blocks Input/Output Blocks are available: 115 VAC/125 VDC Current sour ce Analog 4 Input/2 Output Block(IC660BBA104) 24/48 VDC Current sour ce Analog 4 Input/2 Output Block(IC660BBA024) Two similar blocks, described in the next chapter, provide 6 outputs for devices that accept 4 to 20mA signals. Two outputs on those blocks can also be used for 0V to 5V signals. Features These blocks provide isolated power to all circuits; no separate power is required for 4 20mA signals. All circuits on the block support independent selection of linear scaling values. These values can be used to convert the internal values into engineering units suitable for the application. A dedicated digital output is provided to drive a Bus Switching Module when a Current Source Analog block is installed in a redundant bus cable system. The 24/48 VDC Bus Switching Module (version IC660BSM021) is required for this. Additional configurable features include: Input alarm detection Output Hold Last State or default Selectable input conversion time up to 400mS CPU Redundancy Output feedback checking These blocks automatically perform the following diagnostic checks: Input Open Wire detection Input high and low alarms Input Overrange and Underrange Output Overrange and Underrange Output Feedback Error Compatibility These blocks are compatible with all Genius bus controllers, PCIM and QBIM modules. Hand held Monitor IC660HHM501E (version 3.7) or later is required for configuration. For a Series Six PLC, the CPU must be rev. 105 or later. For a Series Six Plus PLC, rev. 110 or later is required. The programming software must be Logicmaster 6 rel. 4.02 or later. For a Series Five PLC, the CPU must be rev. 3.0 or later. The Logicmaster 5 programming software must be rel. 2.01 or later. A Bus Switching Module must be the 24/48 VDC 11 GEK-90486D-2 Chapter 11 Current-source Analog 4 Input/2 Output Blocks 11-3 Block Operation These blocks have four independent inputs and two independent outputs. Input Circuits Input channels use voltage to frequency converters and counters to translate analog currents to a digital value. This value is converted by the block to engineering units before it is sent to the CPU. a43728 Each input has a 24 volt current loop power supply, capable of providing 25mA of current. Each input is isolated from all other circuits within the block. Input accuracy is 0.1%. Input conversion time can be selected to provide the appropriate combination of noise rejection and input resolution. Conversion times are programmable from 16mS to 400mS. Resolution increases as the conversion time is lengthened. Input resolution is 1mA for 200mS conversion time. Input Data Format Each bus scan, a Current source Analog I/O Block broadcasts 8 bytes of input data. Each input consists of 2 bytes of scaled engineering units data. Appendix B shows reference usage for a Series 90, Series Six, or Series Five PLC. 11 11-4 Genius I/O Discrete and Analog Blocks User s Manual September 1993 GEK-90486D-2 Output Circuits The two independent output circuits are electrically common to each other and the Bus Switching Module outputs, but isolated from all other circuits on the block. Power for the outputs current loops is provided by the block. Output channels use a dual 12 bit digital to analog converter, and can independently control currents from 0mA to 24mA. Output accuracy is 0.15% at 25 C. Output resolution is 6mA. 24VDC P.S Processor a43729 16 Bit Counter V to F Opto Isol. Feedback Amp. Current Sensor Current Controller D/A Feedback 12 Bit Processor Opto Data control D to A Isol. RTN Case GND Ground BSM Switch 15VDC 15VDC OUT BSM BSM Two additional A to D channels are used to check the two output channels after a programmable settling time. The block will indicate a fault if the feedback from these channels does not match the commanded value to within 250mA. Output Data Format Each bus scan, the CPU sends a Current source Analog I/O block 4 bytes of output data. Each analog output consists of 2 bytes of engineering units data. 11 GEK-90486D-2 Chapter 11 Current-source Analog 4 Input/2 Output Blocks 11-5 Hand held Monitor I/O Display Inputs and outputs are always reported and received as whole integers. For example, if the current value of a temperature input was 116.37F, it could be reported as: 116 degrees, or 1163 tenths of degrees, or 11637 hundredths of degrees Here, the example input, configured as hundredths of degrees, is input 1 on the Monitor Block screen. 11 11-6 Genius I/O Discrete and Analog Blocks User s Manual September 1993 GEK-90486D-2 Diagnostics Current source Analog I/O Blocks perform the diagnostics described below. If a fault occurs, the block will report it to the Hand held Monitor, and take appropriate corrective action. Individual circuits can be configured not to send a diagnostic message to the CPU if a fault occurs. If the CPU requests diagnostic information from the block using a Read Diagnostic datagram, the block returns current diagnostics for all circuits, including any with CPU fault reporting disabled. Input Open Wire Diagnostic The block monitors input current levels. If input current is below 2mA, the block sends an Open Wire message. Alarm Thresholds An individual low alarm and high alarm threshold can be configured for each input. If an input reaches one of its configured limits, the block sends a High Alarm or Low Alarm message. Since the circuit s current value is also available, it is possible to determine how much beyond the limit the input is. Only one diagnostic message is sent upon reaching the limit. Input Underrange and Overrange Diagnostics The block sends an UNDERRANGE message if current is negative, or 0mA. It sends an OVERRANGE message if the input signal exceeds 25mA. Output Underrange and Overrange Diagnostics The block sends an UNDERRANGE message if conversion of the engineering units output it receives from the CPU results in a commanded output less than 0mA. It sends an OVERRANGE message if conversion of the engineering units output it receives from the CPU results in an output signal level that exceeds 24mA. The block clamps the output to the selected range limit to protect external hardware. Output Feedback Error This diagnostic is used to detect wiring errors or other hardware faults on output circuits. After waiting for a configurable period of time, the block compares each output s current to its last commanded output value. If the difference is greater than 250mA, the block reports a Feedback Error. The block continues sending new values from the CPU to the output. Nuisance diagnostics may be reported if the Output Feedback Time selected for the circuit is too brief. If this happens, increase the feedback time or disable output feedback testing. GEK-90486D-2 Chapter 11 Current-source Analog 4 Input/2 Output Blocks 11-7 Field Wiring Terminals 5 through 32 are used for input power, Bus Switching Module control, and field wiring devices. These terminals accept AWG #22 to AWG #14 wires. Do not overtorque the terminal screws. The ground (GND) terminal (5) is for block safety. It is connected to the block chassis, and to terminals 13, 16, 20, 24, 28, and 32 which are marked GND. Each channel has one ground terminal for shield termination, if desired. Power Source Wiring Connect an appropriate power source to terminals 6 and 7. For AC block power, connect the source to the H terminal and neutral to the N terminal. For DC block power, connect the source to the DC+ terminal and the return to the DC terminal. Wiring for I/O Devices Typical wiring for various configurations is shown at right. Self powered or externally powered transmitters are wired differently from those powered by the block. External Resistors for Grounded Output Loads If both of the block s output loads are grounded, and the loads are widely separated by distance, an external resistor should be installed in each load s return line to the block. This will prevent possible damage to the block caused by the significant voltage differences that may occur between the two ground points. 10 ohm resistors are suggested. Wiring a Bus Switching Module to a CSA Block When a Bus Switching Module is installed, connect the BSM control wires to terminals 9 and 10. The polarity from the block is as marked; the BSM is insensitive to polarity. 4 Wire Circuit H or DC+ N or DC 11 11-8 Genius I/O Discrete and Analog Blocks User s Manual September 1993 GEK-90486D-2 Block Configuration The configurable features of a Current source Analog 4 input/2 Output Block are listed below. For many, the factory setting may not need to be changed. Feature Channel active Circuit active active, inactive BSM Present Features marked with an asterisk in the table are configured from the Program Block ID screen of the Hand held Monitor, as explained in chapter 3. The rest of the features can be configured either using a Hand held Monitor, or by sending a Write Configuration datagram to the block from the host. Before configuration begins, the block s features should be decided on and recorded on a copy of the Configuration Worksheet printed on the next page. |
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