PTM-1100
Operators
Manual
8
External “Peak Look Window” Timing
As stated above, an external timing signal input (“Peak Look Window”) is required for each
machine cycle to be monitored. This 24 VDC signal can be generated by a dry contact, prox
probe, or PLC output. In general, the timing signal should start shortly before the forming
load begins for the new cycle, and should end shortly after the forming load is finished. In
effect, the timing signal “tells” the module when to “look” at the forming signal for each cycle,
and to capture the “Peak” load value within that time frame. This occurs when the timing
signal is “On”. When the timing signal is “Off”, and provided that the toggle switch is set to
the lower “A/Z” (Auto-Zero) position, the “Auto-Zero Balance” function is turned on to maintain
a proper zero balance reference. “Auto-Zero” is turned off when the timing signal is on, and
load is occurring. At the start of each new timing signal, a “Peak Reset” function happens to
reset the previous peak value, and to start the “Peak Capture” for the new machine cycle.
Normal Operation
After the set-up and calibration have been completed, the 3-position calibration toggle switch
should be set to the lower “A/Z” (Auto-Zero) position for normal operation. This allows the
“Auto-Zero Balance” function to operate between active load cycles, maintaining a proper
zero reference for accurate signal output values.
As the machine is cycled and load is placed on the sensor or load cell, the module will
generate scaled “Track Output” and “Peak Output” analog DC voltage signals. The “Track
Output” is simply the instantaneous signal output from the sensor, and is always on. The
“Peak Output” is controlled by the external timing signal with a “Peak Capture” function, and
is the overall peak signal output from the sensor for a current cycle. It is held in memory at
the end of each timing signal (“Peak Look Window”), and reset to zero by a “Peak Reset”
function at the start of the next timing signal for the new cycle.
In terms of signal output scaling, the PTM-1100 standard is 3 VDC = 100% full scale
capacity. Load values between no load and 100% capacity will yield a proportional output
signal between the particular minimum and maximum output points.
