This what you wanted it to look like?? OkiePC November 11th, You can use them on branches, already populated with blank instructions or partially addressed ones.
I think you should be careful running the two hand tie down function through the PLC. As with any safety circuit you should not rely on the PLC. The two hand control must be implemented by specific safety component as recognised in Europe under the machnery directivei.
The only exception to the above is to use a safety programmable device such as the micro safe PLC, e. If you require any further claification please let me know. By Weir, Bryan on 24 January, - 3: This must be hardwired. By R A Peterson on 29 January, - 5: The odd part is that I have seen it implemented by using a two-handed PB module with its output sent directly to the PLC and the PLC then initiating the desired action.
The hard wired stuff makes a lot of sense for punch press type applications, but is really not applicable directly to a process controlled by a PLC. On a few machines that required a manual clampup, they would use one of the two hand PBs as the clamp signal.
If the light curtain was free, and both PBs were pressed, that was a cycle start signal. I never liked this approach much, but the way the machine was mechanically designed I figured it was not worth arguing over as it was not a punch press, and was designed in such a way as getting ones hands caught in something was just about impossible.
I generally lobbied for hardwiring the light curtain output into the table control so it could not move while the light curtain was broken, but alas the customer did not like this approach and had the PLC enable the table rotation. In my mind, this is the only "safe" way to implement loading parts into a dial type machine, and still have the machine practical.
Of course this reduces the need for operators, which may or may not be good, depending on your POV. By Mark Meng on 29 January, - 5: That implies, safety operation controlled by software is allowed, but needs to be certified.
Mark By Michael Griffin on 24 January, - 4: There has been a change over the last few years in what many people consider to be accepted practice in safety applications, and this includes moving certain safety functions out to dedicated hardware. You can find information on anti tie down relays and other types of safety relays and their application in the literature which the manufacturers provide.
The largest manufacturers of these devices seem to be Jokab and Pilz, but a number of other companies are also in the business Schmerzal, Banner, Siemens, etc. The main point is to have a redundant interface or what is considered to be a fail safe design.
This means that the trigger devices need to be checked on open and close and there needs to be more than one contact per hand to verify the operation.power wire harness and anti tie-down relay are installed: Black (13) Connect to Black (13)14g coming from power circuit board Black (L1) Connect to On/Off switch, opposite black (L1) from circuit breaker behind White (L2) Connect to one of the (L2) 20ga white wires coming from On/Off switch.
BQ and BQC Quadplex or 1-pole Type BD Duplex Circuit Breakers. (Handle Mounted) HLW1 10 Hold-Down Kits Hold-down retainer kit for 3-pole Type BR Circuit Breakers in S and R Loadcenters only.
BRHDB 1 Hold-down screw kit for 2-pole Type BR Circuit Breakers in single-phase MLO Loadcenters . ANTI TIE DOWN WEB LAD 6 - ANTI TIE D Total Rungs in File = 10 Page 1 Sunday, August 20, - ANTI TIE DOWN CIRCUIT EXAMPLE e. ANTI TIE DOWN WEB LAD 6 - ANTI TIE D Total Rungs in File = 10 Page 1 Sunday, August 20, - ANTI TIE DOWN CIRCUIT EXAMPLE e.
Write a program for an “anti–tie down circuit” that will disallow a punch press solenoid from operating unless both hands are on the two palm start buttons. Both buttons must be pressed at . A "two-hand no tie down" routine eliminates this by performing a timed check on the two separate inputs to make sure one is not tied down.
Our code example allows for a sec window of time in which the second button must be pressed.