TH27722A - The bus and bus access circuits are used to connect the programmable logic controller components to the bus. - Google Patents

Abstract

DC60 (04/04/40) In the case of a programmable logic controller with a modular structure to allow the insertion and removal of the components (2,3) even during operation without disturbance of the data traffic occurring through the bus (5) of the programmable logic controller, the supply is made according to the device for the arrangement of the evaluation circuit (13) in the bus section or the bus access circuit (20). The evaluation circuit (13) establishes whether the components (2,3) are connected to the bus (5) and, accordingly, controls the variable resistor (12), which is provided in one supply line (11',11'') for the components (2,3) to have high or low resistance. In the case of a modular programmable logic controller that allows the insertion and removal of components (2,3) even during operation without disturbing the data traffic occurring through the programmable logic controller's bus (5), the provision is made according to the designation for the arrangement of the evaluation circuit (13) in the bus section or the bus access circuit (20). The evaluation circuit (13) establishes whether the components (2,3) are connected to bus (5) and, accordingly, controls the variable resistor (12), which is provided in one supply line (11',11'') for the components (2,3) to have high or low resistance.

Claims (5)

1. The bus section for connecting the component set (2,3) of the programmable logic controller to bus (5) - The bus section with at least the first and second supply lines (4,4'''') and signal lines (4-1 to 4-n), as well as the plug position (10) for inserting the component set (2,3) - The plug position (10) with at least the first and second supply contacts (10'',10'''') and signal contacts (10-1 to 10 n) - The lines (4'',4'''',4-1 to 4-n) of the bus section connected via the corresponding actuation lines (11'',11'''',11 to 11-n) to the corresponding contacts (10'',10'''',10-1 to 10 -n) of the plug position 10 with characteristics - That the insertion position (10) has at least one additional test contact (14) which is connected to the first supply line (4'') through the pull-up resistor (15) can be connected to the second supply line (4'''') through the assembly (2,3) and connected to the evaluation circuit (13) and - that the evaluation circuit (13) is connected to the supply line (4'',4'''') evaluates the potential (Up) appearing at the test contact (14) and controls the variable resistor (12) which is arranged in the first trigger line (11'') to have high resistance if the potential (Up) appearing at the test contact (14) corresponds approximately to the potential (Uo) of the first supply line (4''). 2. Bus access circuit for connecting the (2,3) assembly of the programmable logic controller to bus (15) - Bus access circuit (20) which has at least one bus connection (21) to bus (5) and at least one plug position (10) for inserting the (2,3) assembly - Each bus connection (21) and plug position (10) has at least one first and second supply contact. (10'',10'''',21],21'''') and signal contacts (10-1 to 10-n,21-1 to 21-n) - corresponding contacts (10'' and 21'',10'''' and 21'', 10-1 and 21-1 to 10-n and 21-n) of bus connection (21) and plug-in positions (10) that are supplied together via corresponding connection lines (11'',11'''',11-1 to 11-n) - that additional plug-in positions (10) are at least One of the second test contacts (14), which is connected to the first supply contact (21'') of the bus connection (21) through a pull-up resistor (15), may be connected to the second supply contact (21'') of the bus connection (21) through assembly (2,3) and connected to the evaluation circuit (13), and - that evaluation circuit (13) is connected to the supply contacts (21'',21'''') of the bus connection (21), evaluates the potential (Up) appearing at the test contact (14) and controls the variable resistor (12) which is provided in the first supply line (11'') to have high resistance. If the potential (Up) appearing at the test contact (14) corresponds approximately to the potential (Uo) of the first supply contact (21'') of the bus connection (21), 3. The bus section under claim 1 and the bus access circuit under claim 2 are characterized in which the evaluation circuit (13) controls a variable resistor (12) to have a resistance so low that when the potential (Up) appears at the test contact (14) it corresponds only to the potential of the second supply line (4'''') and, in sequence to the second supply contact (21'''') of the bus connection (21), in a manner that is uninterrupted during the predetermined waiting time (T1). 4. The bus and bus access circuits under claim 3 have the characteristic that the evaluation circuit (13) gradually controls the variable resistor (12) to have low resistance. 5. The bus and bus access circuits under claim 3 or 4 have the characteristic that the evaluation circuit (13) is connected to the first supply contact (10) of the insertion position (10), and that the evaluation circuit (13) controls a variable resistor (12) to give it a higher resistance if, after a predetermined stabilization time (T2), the potential (U) of the first supply contact (10'') of the insertion position (10) is outside the predetermined range. (Clause 5, page 2, figure 5)