Abstract:
One embodiment is a method comprising coupling a simulator card to a first adapter module; coupling the first adapter module to a first programmable logic controller card; and outputting signals from the simulator card to the first programmable logic controller through the first adapter module. Another embodiment is an apparatus for testing a programmable logic controller card comprising a simulator card for generating output signals; a first connector coupled to the simulator card; and a adapter module including a second connector and pin outs; wherein the first connector is detachably coupled to the second connector.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to programmable logic controller simulators. More specifically, the present invention relates to a modular interface card for programmable logic controller simulators.  
         [0003]     2. Discussion of the Related Art  
         [0004]     During the process of developing a machine or device that uses a programmable logic controller (PLC) it is often necessary to generate analog and/or digital signals to test the PLC after it has been programmed. In order to ensure the PLC is properly programmed analog and/or digital signals are input into the PLC to simulate conditions like pressure, temperature and switch contacts on real machines that the PLC will be used with. The testing is done for debugging the programmed PLC, controlling the process, or verifying machine response during alarm conditions.  
         [0005]     Currently many programmers of PLCs build simulators in large enclosures with wires going to the PLC in order to generate the analog or digital input signals. This is a bulky solution that is not easily transferred between different PLCs. Furthermore, the enclosures can be very time consuming to build and the wiring within the enclosure can easily become crossed leading to hours of debugging.  
       SUMMARY OF THE INVENTION  
       [0006]     The different embodiments described herein address the above-mentioned needs as well as other needs by providing a simulator card including and adapter module.  
         [0007]     One embodiment can be characterized as a method comprising coupling a simulator card to a first adapter module; coupling the first adapter module to a first programmable logic controller card; and outputting signals from the simulator card to the first programmable logic controller through the first adapter module.  
         [0008]     Another embodiment can be characterized as an apparatus for testing a programmable logic controller card comprising a simulator card for generating output signals; a first connector coupled to the simulator card; and a adapter module including a second connector and pin outs; wherein the first connector is detachably coupled to the second connector.  
         [0009]     Yet another embodiment can be characterized as a system comprising a simulator card for generating input signals, the simulator card including a first connector; a first adapter module including a second connector and a first set of pin outs, the first adapter module adapted to be detachably coupled to the simulator card; and a second adapter module including a third connector and a second set of pin out, the second adapter module adapted to be detachably coupled to the simulator card; wherein the first adapter module is designed for being coupled to a first programmable logic controller card; wherein the second adapter module is designed for being coupled to a second programmable logic controller card.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings, wherein:  
         [0011]      FIG. 1  is a block diagram illustrating a simulator card coupled to an adapter module in accordance with one embodiment;  
         [0012]      FIG. 2  is a diagram illustrating a simulator card coupled to an adapter module in accordance with another embodiment;  
         [0013]      FIG. 3  is a diagram illustrating side cross sectional view of the simulator card and the adapter module shown in  FIG. 2  in accordance with one embodiment;  
         [0014]      FIG. 4  is a diagram illustrating a programmable logic controller (PLC) card in accordance with one embodiment; and  
         [0015]      FIG. 5  is a flow diagram illustrating a method connecting a simulator card to a PLC card in accordance with one embodiment. 
     
    
       [0016]     Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions, sizing, and/or relative placement of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will also be understood that the terms and expressions used herein have the ordinary meaning as is usually accorded to such terms and expressions by those skilled in the corresponding respective areas of inquiry and study except where other specific meanings have otherwise been set forth herein.  
       DETAILED DESCRIPTION  
       [0017]     The following description is not to be taken in the limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.  
         [0018]     Referring to  FIG. 1 a  block diagram is shown illustrating a simulator card coupled to an adapter module in accordance with one embodiment. Shown is a simulator card  100 , an adapter module  102 , and a programmable logic controller (PLC) card  104 . The simulator card is electrically coupled to the adapter module  102 . The adapter module  102  is electrically coupled to the PLC card  104 .  
         [0019]     The simulator card  100  in one embodiment is a printed circuit (PC) board that generates inputs for testing the PLC card  104 . The simulator card  100  generates digital and/or analog inputs. The simulator card  100  optionally includes a power supply, however, an external power source is used in some embodiments. The simulator card  100  also includes a connector for mating with the adapter module  102 .  
         [0020]     The adapter module  102  is a PC board that includes a connector portion and a pin out portion in accordance with one embodiment. The connector portion mates with the connector of the simulator card  100 . The pin out portion connects with the PLC card  104 . In order to support the transferability of the simulator card  100  between many different PLC cards that have different pin out or input connections, the adapter module  102  can be easily removed and replaced. Each PLC card has a different pin out configuration, thus, instead of having a simulator card  100  for every PLC card  104  on the market, the simulator card  100  is electrically coupled to the adapter module. In one embodiment, each PLC card  104  has a different adapter module  102  with pin outs that correspond to the specific PLC card. Advantageously, this provides for a very inexpensive solution for interchanging a simulator card  100  between different PLC cards.  
         [0021]     The PLC card  104  is any type of programmable controller. Optionally, an adapter module  102  is developed for each PLC card that is available. However, for example, when two different PLC cards have the same pin out configuration, one adapter module  102  can optionally be used for the two different PLC cards.  
         [0022]     Referring next to  FIG. 2 a  diagram is shown illustrating a simulator card coupled to an adapter module in accordance with another embodiment. Shown is a simulator card  200 , a plurality of controls  202 , circuitry  204 , a first connector  206 , an adapter module  208 , a second connector  210 , and pin outs  212 .  
         [0023]     The simulator card  200  includes the plurality of controls  202 , the circuitry  204 , and the first connector  206 . The adapter module  208  includes the second connector  210 , and the pin outs  212 . As is shown, the first connector  206  of the simulator card  200  connects with the second connector  210  of the adapter module  208 . In one embodiment, the simulator card  200  and the adapter module  208  are PC boards.  
         [0024]     The plurality of controls  202  are, for example, knobs or switches. To simulate digital signals toggle switches are used in one embodiment to turn the outputs of the simulator card on or off corresponding to a high or low digital signal, respectively. In one embodiment, manual switches are used, however, other types of switches such as are known in the art can be used. To simulate analog signals knobs are used to control variable resistances. The variable resistances create different current outputs. For example, knobs are used to vary the resistance of potentiometers. The variable resistance along with the circuitry then generates outputs, for example, between 4 milliamps and 20 milliamps.  
         [0025]     In one embodiment, the circuitry comprises simple circuitry for generating the digital or analog outputs that are controlled by the plurality of controls  202 . To generate digital outputs, transistors connected to the controls (for example, switches) are used to generate high or low outputs at the first connector  206  of the simulator card  200 . To generate analog outputs, operational amplifiers connected to the controls  202  (for example, potentiometers) generate variable current outputs at the first connector  206  of the simulator card  200 .  
         [0026]     The second connector  210  of the adapter module  208  is electrically coupled to the first connector  206  of the simulator card  200 . In one embodiment, the first connector  206  and the second connector  210  are a male and female type connector such that wiring mistakes between the simulator card  200  and the adapter module  208  are prevented. Other types of connectors, such as are known in the art are used in different embodiments. The pin outs  212  are electrically coupled to the outputs of the simulator card  200  through the second connector  210 . The second connector  210  is electrically coupled to metal traces on a PC board. The metal traces then connect to the pin outs  212 . Optionally, the adapter module  208  includes resistances or other electrical components that can alter the input to a PLC card.  
         [0027]     Advantageously, the adapter module  208  is designed such that the pin outs  212  match with pin outs of a PLC card (shown in  FIG. 5 ). This allows the same simulator card to be used with many different PLC cards by switching to the adapter module  208  designed for the specific input connections of the PLC card. The adapter module  208  is relatively simple in design and inexpensive as compared to the simulator card  200 , thus replacing the adapter module  208  is much more efficient than having a simulator module  200  built for each different PLC card.  
         [0028]     Referring to  FIG. 3 a  diagram is shown illustrating side cross sectional view of the simulator card  200  and the adapter module  208  shown in  FIG. 2  in accordance with one embodiment. Shown is the simulator card  200 , the control  202 , the circuitry  204 , the first connector  206 , the adapter module  208 , the second connector  210 , and the pin out  212 .  
         [0029]     In one embodiment the simulator card  200  and the adapter module  208  are implemented on a printed circuit board. This provides for a compact and reliable testing device that can be interchangeably used with a plurality of PLC cards by removing and replacing the adapter module  208 .  
         [0030]     Referring now to  FIG. 4 a  diagram is shown illustrating a programmable logic controller (PLC) card in accordance with one embodiment. Shown is a PLC card  400  and a plurality of input connections  402 .  
         [0031]     The pin outs  212  of the adapter module  208  (shown in  FIGS. 2 and 3 ) connect with the input connections  402 . Screws are then tightened down to hold the adapter module  208  in place. This provides an electrical connection between the simulator module  200  and the PLC card  400 . Additionally, the output from the simulator card  200  connects to the proper input in the PLC card  400  as the adapter module  208  is designed to match the input connections  402  specific to the PLC card  400 .  
         [0032]     Once the simulator card  200  is electrically coupled to the PLC card  400  through the adapter module  208  the PLC card  400  can be tested.  
         [0033]     Referring to  FIG. 5 a  flow diagram is shown illustrating a method connecting a simulator card to a PLC card in accordance with one embodiment.  
         [0034]     In step  500 , a simulator card is coupled to a first adapter module. The adapter module includes, in one embodiment, a pin out that is designed for a PLC card. In step  502 , the first adapter module is coupled to a first programmable logic controller card. Next, in step  504 , signals are output from the simulator card to the first programmable logic controller through the first adapter module. The signals can be either digital or analog type input signals.  
         [0035]     In another embodiment, the first adapter module is then removed from the simulator card in step  506 . Next, in step  508  a second adapter module is coupled to the simulator card. In step  510 , the second adapter module is coupled to a second programmable logic controller card and in step  512  signals are output from the simulator card to the second programmable logic controller through the second adapter module.  
         [0036]     While the invention herein disclosed has been described by means of specific embodiments and applications thereof, other modifications, variations, and arrangements of the present invention may be made in accordance with the above teachings other than as specifically described to practice the invention within the spirit and scope defined by the following claims.