Measurement Computing USB-ERB24 - Manual (Page 20)

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 24
Relay configuration 2 banks of 8 and 2 banks of 4
Contact configuration 24 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 User-configurable per bank via switch S2 for pull-down (default) or pull-up.
Switch settings can be read back via software.
ƒ
Pull-down will put the relays in non-energized mode on power up.
ƒ 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-9V3A 9 V ±10% @ 3 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 1.5 A typ, 1.8 A max External power consumption
All relays off, 100 mA downstream hub power 230 mA typ, 270 mA max
4-1