Measurement Computing USB-ERB08 - Manual (Page 19)

Chapter 4
Specifications
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.
Output specifications
Table 1. Output specifications
Number of relays 8
Relay configuration 2 banks of 4
Contact configuration 8 Form C (SPDT) Normally Open, Normally Closed and Common available at
screw terminals
Contact rating 6 A @ 240 VAC or 28 VDC resistive
Contact resistance 100 milliohms max (initial value)
Operate time 10 milliseconds max
Release time 5 milliseconds max
Vibration 10 to 55 Hz (amplitude 1.5 mm)
Shock 10 G (11 milliseconds)
Dielectric isolation (between relay
open contact) 300 VAC, 50/60 Hz (1 minute)
Dielectric isolation (between PCB
output lines) 500VAC, 50/60 Hz (1 minute)
Life expectancy 10 million mechanical operations, min
S2 = pull-up Energized. NO in contact with Common Power on state
S2 = pull-down Not energized. NC in contact to Common
Relay control logic polarity User-configurable per bank via switch S1 for invert or non-invert (default).
Switch settings for polarity can be read back via software through the USB bus.
Switch settings do not affect the power on condition. Non-invert mode: when "0"
is written or read back via the USB bus, relays are not energized. Invert mode:
when "0" is written or read back via the USB bus, relays are energized.
Pull-up / pull-down (controls relay
power on state) User-configurable per bank via switch S2 for pull-down (default) or pull-up.
Switch settings can be read back via software. Pull-down will put the relays in
non-energized mode on power up. Pull-up will put the relays in energized mode
on power up.
Power
Table 2. Power specifications
Parameter Conditions Specification
USB +5 V input voltage range 4.75 V min. to 5.25 V max.
USB +5 V supply current All modes of operation 10 mA max
External power supply (required) MCC p/n CB-PWR-9 9 V ±10% @ 1 A
V
ext
< 6.0 V
,
V
ext
> 12.5 V PWR LED = Off (power fault) Voltage supervisor limits - PWR LED
6.0 V < V
ext
< 12.5 V PWR LED = On
All relays on, 100 mA downstream hub power 750 mA typ, 850 mA max External power consumption
All relays off, 100 mA downstream hub power 170 mA typ, 200 mA max
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