Programmable Logic Controllers (PLC) Specifications

Help with Programmable Logic Controllers (PLC) specifications:

 Total Points

	Total Number of Points:		Number of points is the sum of the inputs and the outputs. PLCs may be specified by any possible combination of these values.
	Search Logic:		User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria.

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Number of Instructions

	Number of Instructions:		Instructions are standard operations (such as math functions) available to PLC software.
	Search Logic:		All matching products will have a value greater than or equal to the specified value.

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PLC I/O

	Number of Inputs:		Input signals the PLC can accept.
	Search Logic:		User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria.
	Number of Outputs:		Output signals the PLC can provide.
	Search Logic:		User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria.
	Input
	Your choices are...
	DC Input		Discrete DC voltage or current level.
	AC Input		Discrete AC voltage or current level.
	Analog Input		Variable current or voltage input such as 0-10V, 4-20mA, etc.
	Thermocouple Input		Input for a thermocouple or thermocouple series.
	RTD Input		Input designed for a resistance temperature detector.
	Frequency / Pulse Input		Input from any device that outputs a frequency signal or pulse train.
	Transistor Input		Input from a solid-state device such as a sensor; typically includes choice of sinking or sourcing.
	Interrupt Input		Input for a digital signal that can stop, resume, or redirect a component of the resident software.
	Other Input		Other unlisted or specialized input.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Output
	Your choices are...
	DC Output		Discrete DC voltage or current level.
	AC Output		Discrete AC voltage or current level.
	Relay Output		Switch type output; contacts are open or closed.
	Analog Output		Variable voltage or current level, e.g., 0-10V, 4-20 mA current loop, etc.
	Frequency / Pulse Output		Output is in the form of a frequency or pulse train.  Pulses can be used to trigger or control external devices.
	Transistor Output		Solid-state switch output; typically includes choice of driving a load in sinking or sourcing mode.  Transistors are often used as switches to drive digital logic circuits such as TTL, CMOS, or ECL.
	Triac Output		Semiconductor device used primarily as a switch.  A triac can conduct in both directions, can be triggered by positive or negative voltage, and can precisely control the duty cycle of AC loads.  Triacs can be used in full-wave AC control and switching for applications such as motors, heaters, and air conditioners.
	Other Output		Other unlisted or specialized output.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.

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More Specs

	Scan Time:		Time required by the PLC to check the states of its inputs and outputs.
	Search Logic:		All matching products will have a value less than or equal to the specified value.
	Data Memory:		Capacity for data storage.
	Search Logic:		All matching products will have a value greater than or equal to the specified value.
	Program Memory:		Capacity of memory for control software.
	Search Logic:		All matching products will have a value greater than or equal to the specified value.
	Expandable?		Units may be stacked or linked together to increase total control capacity.
	Search Logic:		"Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
	Maximum Number of Channels:		Maximum total number of input and output channels in an expanded system.
	Search Logic:		All matching products will have a value greater than or equal to the specified value.
	Programming
	Your choices are...
	Front Panel		Integral keypad and display on PLC.
	Handheld Programmer		Interface unit specifically meant to hold in hand while entering program parameters.
	Computer Programmable		PLC interfaced to a supervisory or host computer.
	Other		Other unlisted, specialized, or proprietary programming method.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	PLC Programming Language:
	Your choices are...
	IEC 61131-3		The IEC 61131-3 programming environment provides support for five languages specified by the global standard: Sequential Function Chart, Function Block Diagram, Ladder Diagram, Structured Text, and Instruction List. This allows for multi-vendor compatibility and multi-language programming.
	Sequential Function Chart (SFC)		SFC is a graphical language that provides coordination of program sequences, supporting alternative sequence selections and parallel sequences.
	Function Block Diagram (FBD)		FBD uses a broad function library to build complex procedures in a graphical format. Standard math and logic functions may be coordinated with customizable communication and interface functions.
	Ladder Diagram (LD)		LD is a graphic language for discrete control and interlocking logic. It is completely compatible with FBD for discrete function control.
	Structured Text (ST)		ST is a text language used for complex mathematical procedures and calculations less well suited to graphical languages.
	Instruction List (IL)		IL is a low-level language similar to assembly code. It is used in relatively simple logic instructions.
	Relay Ladder Logic (RLL)		Relay Ladder Logic (RLL), or ladder diagrams, is the primary programming language for programmable logic controllers (PLCs). Ladder logic programming is a graphical representation of the program designed to look like relay logic. Ladder logic programming shows the results of a status check of the inputs and outputs where the conditions are true or not true. The original intent of RLL was to provide a way for the controller to solve logic sequences involving discrete signals.
	Flow Chart		Flow Chart is a graphical language that describes sequential operations in a controller sequence or application. It is used to build modular, reusable function libraries.
	C		C is a high level programming language suited to handle the most complex computation, sequential, and datalogging tasks. It is typically developed and debugged on a PC.
	BASIC		BASIC is a high level language used to handle mathematical, sequential, data capturing and interface functions.
	Other / Proprietary		This category includes any unlisted or proprietary languages.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Application Software Included?		For control or for monitoring PLC processes from a separate supervisory or host computer.
	Search Logic:		"Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
	Computer Interface
	Your choices are...
	Single Serial Interface		Serial communication protocol such as RS232, RS485, USB (one port).
	Multiple Serial Interface		Serial communication protocol such as RS232, RS485, USB (more than one port).
	Parallel Interface		Parallel communication protocol such as GPIB / IEEE 488 / HPIB Protocol.
	Modem		Connectivity through a dial-up modem to a remote computer.
	Other		Unlisted or special requirements such as TTL, RF transmitter, etc.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Transfer Rate:		Baud rate is the transmission speed in bits per second.
	Search Logic:		All matching products will have a value greater than or equal to the specified value.
	Networkable System?		PLC may be networked with additional controllers or other system nodes.
	Search Logic:		"Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
	Network
	Your choices are...
	Ethernet		A standard method of connecting computers to a local area network (LAN) using coaxial cable.
	CANbus		CANbus is a high-speed serial data network engineered to exist in harsh electrical environments.
	DeviceNet		DeviceNet is a network designed to connect industrial devices such as limit switches, photoelectric cells, valve manifolds, motor starters, drives, and operator displays to PLCs and PCs. The network eliminates hard wiring while providing device-level diagnostics.
	SDS		Smart Distributed System (SDS) is an advanced bus system for intelligent sensors and actuators using CAN-based technology.
	VME Bus		VersaModule Eurocard bus, a 32-bit bus developed by Motorola, Signetics, Mostek and Thompson CSF. It is widely used in industrial, commercial and military applications with over 300 manufacturers of VMEbus products worldwide. VME64 is an expanded version.
	Foundation Fieldbus		A bi-directional communications protocol used for communications among field instrumentation and control systems.
	Profibus		PROFIBUS is a vendor-independent, open field bus standard used in a wide variety of manufacturing and process automation applications.
	ARCnet		Attached Resources Computing Network (ARCnet) is a high-speed token-based network technology used to provide LAN communications between computers in both the industrial and commercial marketplaces.
	SERCOS		SErial Real-time COmmunications System (SERCOS) is an open controller-to-intelligent digital drive interface specification, designed for high-speed serial communication of standardized closed-loop data in real-time over a noise-immune, fiber-optic cable.
	IEEE P1451		A standard designed to produce network-capable, network-independent smart sensors. With the standard, all transducers are identical, regardless of the target network or fieldbus.
	Interbus-S		InterBus-S is a fieldbus network based on cyclic serial transmission of input/output data between a master and slave stations.
	Seriplex		The SERIPLEX Control Bus is a control network for simple control and sensing devices, designed for connecting even the simplest of devices, such as pushbuttons, contactors, valves, and limit switches, directly to the network.
	AS-I		Autonomous System, a unique number identifying an Internet-connected network that has routing policies distinct from their upstream connection(s).
	Beckhoff I/O		A communications system that couples open fieldbus protocols to Beckhoff's Bus Terminal I/O. This allows connectivity to a large variety of devices on the Bus Terminal (K-bus).
	Sensoplex		This system allows direct interconnection of field devices, such as sensors and actuators, to a controller via a single coaxial cable.
	FireWire® IEEE 1394		The IEEE 1394 standard is a scalable, flexible, digital interface designed by Apple Computer, Inc., to integrate the worlds of consumer electronics and personal computers. The IEEE 1394 standard defines both a back plane physical layer and a point-to-point cable-connected virtual bus implementations. FireWire, Apple's implementation of IEEE 1394, is a fast peripheral standard for use with multimedia peripherals such as video camcorders and other high-speed devices like the latest hard disk drives and printers.
	Other		Other unlisted, specialized, or proprietary network systems.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Features
	Your choices are...
	Nonvolatile Memory (EEPROM, etc.)		Storage such as a battery backup, EEPROM, UVPROM, etc.
	Visual Indicators		Indicators such as LEDs for monitoring status.
	Integral Power Supply		Power supply comes with PLC or in same physical package.
	Surge Protection		Circuitry to protect controller from spikes, surges, etc., in supply line voltage.
	Timer(s)		Timers can measure or monitor elapsed time of a sequence or sequence series.
	Counter(s)		Can track or log signals or pulses as a counter.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Maximum Counting Frequency:		Sampling frequency of counter.
	Search Logic:		All matching products will have a value greater than or equal to the specified value.
	PLC Power
	Your choices are...
	12V DC
	24V DC
	Other DC
	115V AC
	230V AC
	Other AC
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Mounting
	Your choices are...
	PC Board		PC card designed to be directly plugged into a computer backplane.
	Panel / Chassis Mount		Designed to be bolted onto a wall or into a cabinet.
	Modular		Modular styles may include controllers that dock in bays in a larger box; designed to be easily stacked and interfaced.
	DIN Rail		Designed for mounting on a DIN rail.
	Rack Mount		Rack-mounted such as in a standard 19" rack.
	Stand-alone		Design is benchtop or floor-standing with full casing or cabinet.
	Other		Any unlisted mounting configuration.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Operating Temperature:		This is the full required range of ambient operating temperature.
	Search Logic:		User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria.
	Operating Humidity:		This is the full required range of ambient operating humidity.
	Search Logic:		User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria.

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