Patent ID: 8612935

Claim:
An input supporting method of a variable name for specifying the variable name as an operand of a command in programming of a programmable controller (PLC), wherein a computer comprises at least a processor and an input device and supports selecting the variable name from a variable table in which at least one variable name scheduled to be used in a user program is registered in advance with an attribute thereof, the method comprising: a first step of obtaining, using the computer, a state, wherein one character of a character can be inputted using the input device; a second step of extracting, using the computer, when the one character is inputted, from the variable table, all variable names that forward match with a character string, comprising a character string, confirmed up to now and the one character; a third step of completing, using the computer, the specification of the operand of the one command by confirming the variable name as the operand in a case where the number of the extracted variable names is one; and a fourth step of confirming, using the processor of the computer, a forward matching portion including a continuous character string of all extracted variable names with each other as the confirmed character string before returning to the first step, in a case where the number of extracted variable names is more than one and the continuous character string matches among all the extracted variable names; wherein, prior to obtaining the state in the first step, the method further comprises a preliminary narrow-down step of narrowing down, using the computer, variable names that can be targeted for extraction to at least one variable name having a data type that can be specified as the operand of the command; wherein the method further comprises a display step of displaying, using the computer, on a predetermined display, the character string determined as the confirmed string in the fourth step; and wherein the display step further includes a step of sequentially displaying, using the computer, the character string determined as the confirmed character string in the fourth step and a non-confirmed character string following the confirmed character string in one of the variable names extracted in the second step, wherein the confirmed character string is displayed in a first display mode and the non-confirmed character string is displayed in a second display mode.