9
A N T I
– T I E – D O W N
With this mode active, FS1 must be made first. The FS2 must follow within 10 milliseconds to 500
milliseconds after. If switch closures occur before or after this operational window, the control will lock
up until both switches are reset or cleared.
Once squeeze mode has begun timing, the weld valve output will activate. If either FS1 or FS2 is opened
during squeeze, the weld valve output will shut off. The squeeze time indicator will remain on. Both FS1
and FS2 must be cleared before sequence can be restored.
A N T I
– T I E – D O W N, T I M E M A I N T A I N E D
With ANTI-TIE-DOWN , selected, a time variable can be set to maintain the FS1 and FS2 inputs for a
pre-set time once both FS inputs are made (within the operational window).
This feature is operational in seam and repeat spot modes
The timer “latches” and begins timing after the initial squeeze time completes. If in repeat mode,
subsequent squeeze times are included in the pre-set latching time. If the repeat and seam modes are off,
then timer defaults and acts like a normal anti-tie-down mode.
To set the timer register, advance to the IMPULSES register with the “B” key. Then press and hold the
“F” key for 2 seconds. The display will start flashing. The units and tens of seconds are entered (00-99).
Press the “A” key to allow tenths of a second entry (.0 to .9) as indicated with a decimal point. The total
range of the timer is .1 to 99.9 seconds. Pressing the “B” key again will exit the timer register.
If the timer register is left at 0 (default), the control responds directly to the FS inputs.
L I N E V O L T A G E M O N I T O R
Circuitry will monitor the line voltage continuously. Operation of the P280 will be inhibited if the line
voltage drops below 90 vac for a period exceeding 30 cycles of 60 hz, and an audible alarm will sound.
The control will not resume operation until the line voltage raises above 93 vac and the control is reset by
either the reset button (S1) located on the PSIO board, or power to the control is cycled off and back on. A
normal POWER ON action will not cause lockup. A “ragged” or “jittery” POWER ON may cause lockup
and require use of the reset button.