Rockwell Automation EK-44750C Enwatch Unit - Manual (Page 18)

Rockwell Automation Publication GMSI10-IN001A-EN-P - May 2013
18 Enwatch Unit
Sample length Multiple of 256 bytes, maximum sample 32768 bytes if no trigger, 16384 bytes with pre-trigger (not used in first version of
Enwatch)
Filter settling time HP 0.36 Hz 18 seconds
HP 2.67 Hz 3 seconds
HP 5.3 Hz 1.2 seconds
HP 23.8 Hz 0.3 seconds
Integrator HP 0.36 Hz 25 seconds
Integrator HP 2.67 Hz 8 seconds
Integrator HP 5.3 Hz 1.5 seconds
Integrator HP 23.8 Hz 0.8 seconds
gSE 200 Hz 88 milliseconds
gSE 5 kHz 2 milliseconds
Core 0.7 seconds
Time constant of 0.03 seconds 300 milliseconds
Time constant of 0.006 seconds 60 milliseconds
Time constant of 0.0012 seconds 12 milliseconds
Time constant of 0.00024 seconds 3 milliseconds
Trigger delay 0-32768 samples. The Emonitor software always uses 0.
Trigger channel 1-4 channels, TTL input 5-20 V
Maximum combined trigger current (channels 1-4), not to exceed 100mA.
Gain control X1, X10, X100, X1000, X5, X50, X500, X5000
Download X1 always. The Enwatch unit autoranges and returns back the current gain for rescaling.
Anti-Alias filter 20 kHz, 2 kHz, 500 Hz, 100 Hz. This is read only. The Enwatch unit selects the proper filter.
gSE time constant 0.03, 0.006, 0.0012, 0.00024 seconds, the default is 0.03 seconds
if FMAX > 350Hz set to 0.00024 seconds
else if FMAX > 150 Hz set to 0.0012 seconds
else if FMAX > 37.5 Hz set to 0.006 seconds
If the measurement is overall only (no spectrum) then set to 0.03 seconds.
Integrator One level of hardware integration
The hardware has a gain factor of:
2.67/f for the 0.36 Hz and the 2.67 Hz filter ranges (INTHI = 0)
38.9/f for the 5.3 Hz and 23.7 Hz filter ranges (INTHI = 1)
To convert from g->ips:
Velocity (ips peak) = [integrator output (volts peak)] x [1 / (gain factor)] x [accel scale factor
(g peak / mv peak)] x [61.24 / frequency]
Sample sequence allowed 4096 - one sample sequence uses one configuration table
Configuration tables 128 - one measurement point uses one table so the total is 128 points
Storage overhead 18 bytes per allocation
Flash memory lifetime 100,000 writes
Total available memory 640 Kilobytes
HOST software support (Emonitor) Window types: Hanning, Hamming, Rectangular, Kaiser Bessel, Flattop
Number of lines 100, 200, 400, 800, 1600, 3200
Number of averages 1-99
Table 2 - Enwatch measurement capabilities
Product Feature Capability