Measurement Computing USB-1208FS-Plus - Manual (Page 19)

USB-1208FS-Plus User's Guide Functional Details
19
Synchronized operations
You can connect the SYNC pin of two devices together in a master/slave configuration and acquire data from
the analog inputs of both devices using one clock.
When the SYNC pin is configured as an output, the internal A/D pacer clock signal is sent to the screw
terminal. Output the clock signal to the SYNC pin of a second device that is configured for A/D pacer input.
Power
Connecting the device to a computer draws <100 mA of current from the USB +5V supply. When running
applications, the current that can be drawn from all device connections (analog, digital, SYNC, and +VO output
loading) is <500 mA. The maximum output current that is available at the +VO power output terminal is
100 mA.
With all outputs at their maximum output current, the USB-1208FS-Plus in a fully-loaded configuration may be
above that allowed by the computer. In this case, determine the per-pin loading in the application to ensure that
the maximum loading criteria is met. The per-pin loading is calculated by dividing +5V by the load impedance
of the pin in question.