5500 Intelligent Display Unit:
HDA 5500 is a microprocessor controlled display and control
unit in standard control panel module housing. A single-chip
microprocessor controls all functions. A maximum of 3
analog inputs and 1 analog output is possible. The analog
input signals are converted by a 10 bit A/D converter
and displayed according to the measuring scale selected
by the user. Each of the 4 maximum possible relays can
be allocated to each of the 3 analog sensor inputs or
the differential between sensor signals 1 and 2. All operating
parameters such as switching points and switch-back (i.e.
hysteresis) points can be programmed by means of the MODE
and SET keys. The relays switch as soon as a pre-set switching
point is reached, or after a programmed delay. This function
suppresses the reaction of the relays to short-term and
irrelevant variations such as pressure spikes.