Abstract:
An adjustment test apparatus for AI module is disclosed, which includes a signal generator supplying analog electric quantity to a plurality of the same type of AI modules, and a maintenance PC connected to each AI module, the maintenance PC being connected to each AI module through a USB hub having a port corresponding to each AI module and a USB-RS232 converter connected to each port, the maintenance PC having a function of selecting a port to communicate with each AI module, and a function of monitoring a digital output value corresponding to an input signal provided by the signal generator to each AI module at the time of communication and setting each AI module to correct the output value to a proper value.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an adjustment test apparatus that tests and adjusts the same type of analog input modules (referred to as AI modules) used in an instrumentation controller before the AI modules are incorporated into a product. 
     2. Background of the Invention 
       FIGS. 7 and 8  are block diagrams showing an adjustment test apparatus for AI module in the past. In the adjustment test apparatus in the past shown in  FIG. 7 , AI modules  101  to be adjusted are disposed in a test controller  102 , a maintenance PC  103  and the test controller  102  are connected to each other by a general-purpose communication line such as Ethernet (registered trademark), and, depending on test conditions, each signal to be entered into each AI module is changed by a signal generator  104 , then an adjustment test is performed by the maintenance PC  103 . See JP-A-2010-20603, page 12, FIG. 1. 
     Further, in the adjustment test apparatus in the past shown in  FIG. 8 , an operator connects an AI module  101  and the maintenance PC  103  in a one-to-one correspondence by a general-purpose communication line, and performs an adjustment test in the same way as above. 
     The adjustment test apparatus in the past shown in  FIG. 7 , which is a system in which a plurality of AI modules  101  each having different specifications are incorporated into the instrumentation controller before an adjustment test is performed, includes the test controller  102 , the maintenance PC  103  and the signal generator  104 ; therefore, the size of the apparatus is large, and preparation time for the adjustment test is required. Further, in the adjustment test apparatus in the past shown in  FIG. 8 , the operator has to manually change the connection between the maintenance PC  103  and the signal generator  104  for each of the AI modules  101  to be adjusted, which is time consuming. 
     The present invention is made to solve the above-mentioned problems, and it is desirable to simplify an adjustment test apparatus for AI module, and shorten the time for the adjustment test. 
     SUMMARY OF THE INVENTION  
     An adjustment test apparatus for AI module according to the present invention includes a signal generator supplying analog electric quantity to a plurality of the same type of AI modules, and a maintenance PC connected to each AI module. The maintenance PC is connected to each AI module through a USB hub having a port corresponding to each AI module and a USB-RS232 converter connected to each port. The maintenance PC has a function of selecting a port to communicate with each AI module, and a function of monitoring a digital output value corresponding to an input signal provided by the signal generator to each AI module at the time of communication and setting each AI module to correct the output value to a proper value. 
     In addition, an adjustment test apparatus for AI module according to the present invention includes a signal generator supplying analog electric quantity to a plurality of the same type of AI modules, and a maintenance PC connected to each AI module by a bus. An address is assigned to each AI module. The maintenance PC has a function of communicating with each AI module based on the address, and a function of monitoring a digital output value corresponding to an input signal provided by the signal generator to each AI module at the time of communication and setting each AI module to correct the output value to a proper value. 
     According to the present invention, since a general-purpose apparatus that allows a plurality of AI modules to be connected is constituted, a test controller in which a CPU or a communication card is incorporated is unnecessary, allowing the entire test apparatus to be reduced, and the preparation time for the adjustment test to be shortened. Further, there is no need to change the connections at each adjustment test of each AI module, allowing the operating time to be shortened. 
     The foregoing and other object, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing an adjustment test apparatus for AI module according to Embodiment 1 of the present invention; 
         FIG. 2  is a diagram showing functions of a maintenance PC of Embodiment 1; 
         FIG. 3  is a flow chart showing the operation of adjustment software according to Embodiment 1; 
         FIG. 4  is a block diagram showing an adjustment test apparatus for AI module according to Embodiment 2 of the present invention; 
         FIG. 5  is a diagram showing functions of a maintenance PC of Embodiment 2; 
         FIG. 6  is a flow chart showing the operation of adjustment software according to Embodiment 2; 
         FIG. 7  is a block diagram showing an adjustment test apparatus for AI module in the past; and 
         FIG. 8  is a block diagram showing another adjustment test apparatus for AI module in the past. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiment 1 
     Embodiment 1 of the present invention will now be described with reference to  FIGS. 1 and 2 . The present invention relates to an adjustment test apparatus that tests and adjusts a plurality of AI modules having the same specifications (referred to as the same type) all at once. In  FIG. 1 , a plurality of, eight in the figure of the same type of AI modules  101  (AI ( 1 ) to AI ( 8 )) to be subjected to adjustment tests, are set in the test apparatus in a production line, for example. Input signals that are test input of voltage, current and the like are applied in parallel to the input side of each of set AI modules  101  from the signal generator  104 . A general-purpose USE/RS232 converter  106  is connected to the output side of each of the AI modules  101 , and connected via a USB hub  105  to the maintenance PC  103  in which adjustment software is installed. The USB hub  105  has eight ports, and each port is connected to each of the AI modules  101  through the general-purpose USB/RS 232  converter  106  in a one-to-one correspondence. The USB hub  105  is connected to the maintenance PC  103  via a USE cable. 
     The maintenance PC  103  uses the adjustment software to perform the adjustment test of the AI modules  101  while communicating with the AI modules  101 . The maintenance PC  103  has functions shown in  FIG. 2 ; that is, a function U of setting signal generator output, a function V of detecting the number of AI modules and setting communication ports, a function W of performing AI module output comparison, and a function X of adjusting AI module output. The maintenance PC  103  does not necessarily have the function U of setting signal generator output among of these functions. The function U may be performed by hand power. 
     When an adjustment test is started, the maintenance PC  103  sets (selects) the number of AI modules  101  to be adjusted and the communication ports to be connected. Then, the output from the signal generator  104  is set by the maintenance PC  103 , and, from the signal generator  104 , a given, for example, analog voltage test input signal is applied to each of the AI modules  101  ( 1 ) to ( 8 ). The test input signal values may be set manually or by the maintenance PC  103 . When selecting the port of the AI module  101  ( 1 ), for example, the maintenance PC  103  communicates with the AI module  101  ( 1 ) via the USB hub  105  and the USB/RS232 converter  106 . 
     At the time of communication, the maintenance PC  103  takes (monitors) the output digital signal from the AI module  101  ( 1 ) and performs output comparison, which is intended to, analyze the output digital signal to determine whether the output digital signal represents a predetermined value. Next, the maintenance PC  103  returns an adjustment signal for adjusting the deviation from the predetermined value to the AI module  101  ( 1 ) in order to adjust the output from the AI module  101  ( 1 ), and sets the value. When the adjustment of the AI module  101  ( 1 ) is completed, the maintenance PC  103  selects the next communication port and communicates with the AI module  101  ( 2 ) to perform the similar adjustment. In this manner, the maintenance PC  103  adjusts all the AI modules  101  and completes the adjustment test. The setting of the test input signal values, the selection of the communication port, the monitoring of the output digital signals from the AI modules  101  and the adjustment of the AI modules  101  are all performed by the software installed in the maintenance PC  103 . Therefore, connection changing and switching operations by a switch at the time of the adjustment test are eliminated, and the adjustment test of a plurality of AI modules can be performed all at once on the manufacturing line. 
       FIG. 3  shows an operational flow chart of the adjustment software. The description will be provided with reference to  FIG. 3 . In step ST 01 , the number of the AI modules  101  to be adjusted and the communication ports to be connected are set by the adjustment software in the maintenance PC  103 . Instep ST 02 , the set signal is output from the signal generator  104  to each of the AI modules  101  according to test conditions. In step ST 03 , communication with the AI modules  101  is established via the communication ports set in step ST 01 , and, from the received data, output value comparison is performed. In step ST 04 , the deviation of the output from each AI module from the predetermined value is adjusted. Finally, in step ST 05 , whether communication has completed with all the communication ports set in step ST 01  is checked, and the processing is ended. Therefore, a plurality of AI modules can be adjusted without preparing a test controller, and without connection changes with respect to test conditions, allowing the operating time to be shortened. 
     Embodiment 2 
       FIG. 4  shows an adjustment test apparatus according to Embodiment 2 of the present invention, in which the input sides of eight same type of AI modules  101  (AI ( 1 ) to AI ( 8 )) are connected to the signal generator  104  in parallel. The output side of each AI module is connected to the bus of a general-purpose RS485/RS232 converter  110 , and the RS485/RS232 converter  110  is connected to the maintenance PC  103  by an RS232 cable. An address is assigned to each of the AI modules  101 . 
     The maintenance PC  103  uses the adjustment software to perform the adjustment test of the AI modules  101  while communicating with the AI modules  101 . The maintenance PC  103  has functions shown in  FIG. 5 ; that is, a function U of setting signal generator output, a function Z of detecting the number of AI modules and assigning addresses, a function W of. performing AI module output comparison, and a function X of adjusting AI module output. The maintenance PC  103  does not necessarily have the function U of setting signal generator output among of these functions. The function U may be performed by hand power. 
     When an adjustment test is started, the maintenance PC  103  sets (selects) the number of AI modules  101  to be adjusted and the addresses of the AI modules  101  to be connected. Then, the output from the signal generator  104  is set by the maintenance PC  103 , and, from the signal generator  104 , a given, for example, analog voltage test input signal is applied to each of the AI modules  101  ( 1 ) to ( 8 ). The test input signal values may be set manually or by the maintenance PC  103 . The maintenance PC  103  performs packet communication with the AI module  101  ( 1 ) based on the address of AI ( 1 ) of the AI modules  101 , for example. 
     At the time of communication, the maintenance PC  103  takes (monitors) the output digital signal from the AI module  101  ( 1 ) and performs output comparison, which is the function for analyzing the output digital signal to determine whether the output digital signal represents a predetermined value. Next, the maintenance PC  103  returns an adjustment signal for adjusting the deviation from the predetermined value to the AI module  101  ( 1 ) in order to adjust the output, and sets the value for the AI module  101  ( 1 ). When the adjustment of the AI module  101  ( 1 ) is completed, the maintenance PC  103  selects the next address and performs packet communication with the AI module  101  ( 2 ) to perform the similar adjustment. In this manner, the maintenance PC  103  adjusts all the AI modules  101  and completes the adjustment test. The setting of the test input signal values, the setting of the communication address, the monitoring of the output digital signals from the AI modules  101  and the adjustment of the AI modules  101  are all performed by the software installed in the maintenance PC  103 . Therefore, connection changing and switching operations by a switch at the time of the adjustment test are eliminated, and the adjustment test of a plurality of AI modules can be performed all at once on the manufacturing line. 
       FIG. 6  is a flow chart showing the operation of the adjustment software installed in the maintenance PC  103 . First, in step ST 01 , the number of the AI modules  101  to be adjusted and the communication address of each AI module are set. In step ST 02 , the set signal is output from the signal generator  104  according to test conditions. In step ST 03 , packet communication with the AI module  101  is established via the communication address set in step ST 01 , and, from the received data, output value comparison is performed. Unlike Embodiment 1, the communication contents can be realized by having a communication packet constitution adapted to a dedicated communication. In step ST 04 , the output adjustment of the AI modules  101  is performed by the maintenance PC  103 . In step ST 05 , whether communication has completed with all the communication addresses set in step ST 01  is checked, and the processing is ended. Therefore, as in Embodiment 1, Embodiment 2 can also shorten operating time and simplify the apparatus. 
     Embodiment 3 
     In Embodiment 1 and Embodiment 2, while the functions of the maintenance PC  103  are as shown in  FIGS. 2 and 5 , it goes without saying that, by adding to the adjustment software installed in the maintenance PC  103  a further function for saving information from a card such as the type of the AI module, the adjustment results, the test time and date or the like, an adjustment record (adjustment result evidence) of the AI module can be prepared, and the operating time can be shortened. Note that, the present invention is not limited to the above-mentioned embodiments and the embodiments may be modified without departing from the scope of the present invention as appropriate. Various modifications and alterations of this invention will be apparatus to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this is not limited to the illustrative embodiments set forth herein.