Remote control for PLC

[PiNkYnotBrain]

Use VNC or Remote Desktop on a smartphone to remote in to either the laptop or HMI.

 

[mad4x4]

Exceptions to every rule. Most raw material handling plants have miles of conveyors that start all the time unattended. Usually with blast horns as a warning of impending movement.

But the operator is not climbing in the machine at the time. The horn is a warning to stand clear as movement is imminent

 

[robertmee]

An operator most certainly could be climbing into the "machine". Redoing belt splices, adjusting tracking switches, oiling gearboxes, etc. All out of sight from the start control location. The point is there are many instances of remote control out of line of sight. That's what local disconnects and proper LOTO are for, as it's impractical to guard or cage such systems.

 

[Old Man]

Add a Camera or 2 or 3 for a LIVE inspection?

 

[OkiePC]

Install Anydesk on a smartphone and the PC used for SCADA. Don't fall off the ladder using your phone to try to control the PC. This would mean the PC needs internet access, which is a whole 'nuther can of safety worms.

 

[JesperMP]

1. Have a test/commissoning mode that is selected by a key switch.
2. Create a very simple web-server HMI of your choice only for testing/commisioning. When test/commissioning mode is selected, then use the web-server HMI to select the device to test, and the type of action ON/OFF, UP/OFF, DOWN/OFF etc. If the webserver is reachable by wi-fi, then the person doing the testing can use his smartphone.
3. Arrange a 'dead-man' switch connected to a safety relay. When the dead-man switch is half-pressed, the chosen action is activated. When the dead-man switch is fully-pressed or released, the action is stopped via the safety relay. The dead-man switch can be at the end of a long cable so that you can bring it with you everywhere around the machine.

N.B. You need to consider the speed of actuators. If the actuators are so fast that it is not realistically possible to remove the limbs that may be caught by the movement, then it is not possible, or you need to provide a system for 'safe low speed'.

N.B N.B. in case this is not clear from the above. All of this should be covered by a risk assessment.