dbaumann
Member
Our customer has a Hydra-Draw machine. This machine pulls coiled steel rod through a die and then cuts-to-length. The hydraulic cylinder is controlled by a servo-proportional valve that requires a +/-10VDC command signal. The position feedback devices are an encoder wheel to measure the length of rod, and a Temposonics LH series transducer with start/stop output.to measure the cylinder position. The tempo signal is fed to a Carolina Motion Control AEC-100-24 in order to convert the signal to an encoder signal. Then the two encoder signals are fed to a Modicon MOT-202 motion module.
The reason for the two feedback devices is because while the cylinder moves to “draw” the steel rod through the die, the “grippers” may slip slightly and so the actual length of rod being drawn is measured by the encoder wheel mounted at the cutter blade. So, basically, the encoder wheel determined the cut length, and the Tempo determined the “return to home” position ( because, prior to the cylinder returning to home, the gripper is released and thus the rod does not move hence the encoder wheel does not move). So, their PLC uses the MOT-202 motion module to select which feedback device to use and then send out a +/- 10 VDC command signal to the servo valve in order to control the cylinder’s motion. The encoder wheel for one direction, the Tempo for the other direction.
Our customer wants us to replace the current control system. ( Modicon PLC, Modicon MOT-202 Motion Module, etc, etc ). This is because they have had nothing but problems with the existing system and they are not familiar with Modicon programming. Their plant is 99% A-B PLCs. Consequently, they want us to use A-B for the controls.
They have a SLC-5/03 they would like to use.
I'm thinking of using an 1746-HSCE2 dual encoder module for the feedback and an analog output moudule for the command signal. The customer wants to be able to select the cut length and the draw cylinder speed. Obvioulsy speed and accuracy are their main concern.
Should I be looking at a different way to do this ?
Thank-you in advance for your assistance,
Dave
The reason for the two feedback devices is because while the cylinder moves to “draw” the steel rod through the die, the “grippers” may slip slightly and so the actual length of rod being drawn is measured by the encoder wheel mounted at the cutter blade. So, basically, the encoder wheel determined the cut length, and the Tempo determined the “return to home” position ( because, prior to the cylinder returning to home, the gripper is released and thus the rod does not move hence the encoder wheel does not move). So, their PLC uses the MOT-202 motion module to select which feedback device to use and then send out a +/- 10 VDC command signal to the servo valve in order to control the cylinder’s motion. The encoder wheel for one direction, the Tempo for the other direction.
Our customer wants us to replace the current control system. ( Modicon PLC, Modicon MOT-202 Motion Module, etc, etc ). This is because they have had nothing but problems with the existing system and they are not familiar with Modicon programming. Their plant is 99% A-B PLCs. Consequently, they want us to use A-B for the controls.
They have a SLC-5/03 they would like to use.
I'm thinking of using an 1746-HSCE2 dual encoder module for the feedback and an analog output moudule for the command signal. The customer wants to be able to select the cut length and the draw cylinder speed. Obvioulsy speed and accuracy are their main concern.
Should I be looking at a different way to do this ?
Thank-you in advance for your assistance,
Dave
