Abstract: Plural electrical loads supplied with power from a single source are monitored to detect defective loads. Each load is periodically individually energized and current delivered by the source is measured. Measured current for each load is compared with limit values to detect abnormal values. To overcome consequences of supply voltage fluctuations, supply voltage is also measured and admittance of each load is determined from measured current and measured voltage. The admittance value thus determined for each load is compared with limit values to detect abnormal values. Load monitoring of loads energized according to a control algorithm proceeds by periodic momentary suspension of energization according to the control algorithm and energization of selected individual loads.

Abstract: A control for an injection molding machine is provided including: a processor module producing set point signals in response to detection of coincidence of, selectably, analogue input signals, binary status signals, and elapsed time signals; and, a signal processing module for periodically producing control signals in response to the set point signals, measured parameter signals and control algorithms relating set point values and measured parameter values. A DC output interface module is provided including a plurality of DC output interface circuits for applying binary control signals to machine devices. The DC output interface circuits include self-latching over-current protection including means for sensing a latched condition thereof to produce an over-current fault indicating signal available to the processor module. The processor module includes an expansion bus for connection of the signal processing module and the DC output interface module.