(need to draw and insert this)
The ESTOP chain is a continuous path from +24V, thru many switches and other interlock devices, and terminating in a relay which must be energised for the machine to run. If ANY interlocking device opens, the master ESTOP relay drops out and the machine stops. The last device in
the chain is a relay controlled by EMC, which is used to latch the chain in the open (tripped) state until it is explicitly reset.
The chain is as follows:
- Start (+24V) at top junction box terminal block, 43rd terminal from left, leaves on red wire ESPA.
- Red wire ESPA goes to bottom Z estop switch (farthest forward cam track).
- Switch is NC, opens on overtravel. Signal leaves switch on black wire ESPD.
- Black wire ESPD goes to top junction box terminal block, 50th terminal from left, leaves on blue wire ESPD.
- Blue wire ESPD goes to top Z estop switch (third cam track).
- Switch is NC, opens on overtravel. Signal leaves switch on blue wire ESPA.
- Blue wire ESPA goes to top junction box terminal block, 49th terminal from left, leaves on blue wire ESPA.
- Blue wire ESPA goes to the center vertical terminal block in the power cabinet, 21st from the bottom, where it is labeled ESPC. Signal leaves on blue wire 53.
- Blue wire 53 goes to power cabinet door E-Stop switch.
- Switch is NC, opens when pressed. Signal leaves switch on blue wire 55.
- Blue wire 55 goes to TB32 on inside of cabinet door, 5th terminal from bottom, leaves on blue wire 55.
- Blue wire 55 goes to control cabinet as part of bundle C8, and is labeled 55 at the control cabinet end.
- Blue wire 55 connects to bottom DIN rail terminal 11 in control cabinet, which is jumpered to terminal 12
- Bottom DIN rail terminal 12 leaves in cable PANEL1, gray wire of gray/white pair.
- Gray wire in cable PANEL1 goes to front panel ESTOP switch.
- Switch is NC, opens when pressed. Signal leaves switch in cable PANEL1, white wire of gray/white pair.
- White wire in cable PANEL1 connects to bottom DIN rail terminal 13 in control cabinet, which is jumpered to terminal 14.
- Bottom DIN rail terminal 14 leaves on blue wire ESPB.
- Blue wire ESPB goes to Y axis estop switch (LS52, bottom cam track).
- Switch is NC, opens on overtravel (either direction). Signal leaves switch on green wire.
- Green wire goes to X axis estop switch (front cam track).
- Switch is NC, opens on overtravel (either direction). Signal leaves on blue wire ESPB.
- Blue wire ESPB connects to bottom DIN rail terminal 15 in control cabinet, which is jumpered to terminal 16.
- Bottom DIN rail terminal 16 goes to an EMC input (parport, thru PMDX board, need pin number) which is mapped to HAL pin ESTOP_IN. It also goes directly to the COM terminal of the EMC controlled relay on the PMDX board (wire number ???).
- The relay on the PMDX board is controlled by HAL pin ESTOP_OUT, and also by the charge pump on the PMDX board. The hardware guarantees that the relay will only close if the charge pump input is toggling and ESTOP_OUT is true.
- A HAL component known as an "estop latch" looks at ESTOP_IN and ESTOP_RESET. If ESTOP_IN is false, ESTOP_OUT will go false and remain false until ESTOP_IN is true and a rising edge is detected on ESTOP_RESET. NOTE that even if the PC is totally out of it's mind and ESTOP_OUT is "stuck" true, the machine will still stop, because the PMDX relay doesn't directly control the main ESTOP relay. The signal from the entire ESTOP chain passes thru the PMDX relay, so if the chain goes FALSE, things stop immediately, regardless of what the HAL component and PMDX relay do. Their only role is to latch the fault condition so that when it is cleared you have to hit F1 to restart.
- ESTOP_RESET comes from the core of EMC, and is asserted when the machine is taken out of ESTOP (by hitting F1).
- When the PMDX board relay closes, the ESTOP chain continues thru the relay, leaving the NO terminal, on wire number ???.
- Wire number ??? goes to bottom DIN rail terminal 17, and leaves on blue wire 58
- Blue wire 58 goes to the coil of the main ESTOP relay in the power cabinet (located next to the 120V circuit breakers).
- The other side of the ESTOP relay coil goes to the 24V common.
As a result, the main ESTOP relay will pull in only after all switches are closed, and the machine is off the estop limits (which are located a short distance beyond the normal limits), and the PC is up and running, and the user has hit F1. It will drop out if any of those conditions fails, and will remain out until the condition is resolved and the user hits F1 again.
The main ESTOP relay controls the 120VAC feed from secondary #2 of the main control power transformer (circuit 15). That disables all motor starters and contactors in the system, as well as all of the hydraulic solenoid valves controlled by the solid state relays.
Another pole of the main ESTOP relay interrupts 24V power to "other stuff" (revise later).