
15
The DMX ports are by default not isolated from the MSC’s ground connection
which is the recommended configuration for driving isolated inputs - the
majority of DMX receivers.
If required this may be changed by removing the top cover of the MSC and
removing the jumper marked ‘JP1’, located to the right of the DMX ports. The
two DMX ports will then be optically isolated from the MSC’s internal circuitry
although not from each other.
lDigital/Analog Inputs
The MSC features 8 digital/analog inputs on one 16 way connector. To
connect an input signal to the MSC one connection should be made to the
desired input pin, marked '1' to '8', and the other should be made to the
adjacent signal ground pin.
The inputs can be individually configured via Designer to operate in one of
three modes:
Contact closure: An external volt-free switch may be connected between the
input pin and the signal ground pin.
In this mode, the input pin is internally pulled-up to 5V via a 2.2Kohm resistor,
so the switch only needs to be rated at 5V, 2.5mA or greater.
Digital input: An external voltage source (such as a 12VDC trigger output)
may be connected between the input pin and the signal ground pin.
In this mode, the input pin is internally pulled down to 0V via a 202.1Kohm
resistor and the maximum input voltage supported is 24VDC.
The MSC may be configured to specify what the 'high' and 'low' threshold
voltages are. This facility can be used to provide 'Schmitt trigger' action.
Analog input: An external voltage source (such as a 0-10V analog signal) may
be connected between the input pin and the signal ground pin.
In this mode, the input pin is internally pulled down to 0V via a 202.1Kohm
resistor and the maximum input voltage supported is 24VDC.
The MSC may be configured to specify what the input voltage range is.
Voltages inside this range are reported as 0% to 100%.
In all modes, the maximum rated input voltage is 24VDC. The inputs should
never be driven with a higher voltage nor negative voltage or damage may
occur.
SECTION 2 - MSC