System and method for providing a full fail-safe capability in signal transmission networks
View Patent ↗Systems and methods for providing a full fail-safe capability in signal transmission networks are disclosed. For example, a system for providing a full fail-safe capability in signal transmission networks includes at least a first electronic circuit to transmit and receive signals or data, at least one driver unit coupled to the at least a first electronic circuit, and at least one receiver unit coupled to the at least a first electronic circuit and the at least one driver unit. The at least one receiver unit includes at least one offset signal generating unit, a signal comparing unit, and a switching unit to couple an offset signal from the at least one offset signal generating unit to an input of the signal comparing unit.
1. A method of providing a full fail-safe function in a signal transmission network even if a plurality of data input connections to the signal transmission network are inverted, comprising:
receiving a plurality of digital differential signals across the plurality of data input connections in the signal transmission network;
coupling a first input of the plurality of inputs to a first offset signal generating unit and a second offset signal generating unit;
if a polarity of the plurality of signals is a first polarity, selecting the first offset signal generating unit and thereby adding a first offset signal to the plurality of signals received at the first input;
if the polarity of the plurality of signals is a second polarity, selecting the second offset signal generating unit and thereby adding a second offset signal to the plurality of signals received at the first input, wherein the first offset signal and the second offset signal have opposite polarities; and
outputting a logic signal if the received plurality of signals is the first polarity or the second polarity, and the plurality of inputs are open or floating, shorted together, or shorted with a termination resistor.
2. The method of claim 1 , wherein the first polarity is an inverted polarity and the first offset signal is a positive voltage.
3. The method of claim 1 , wherein the first polarity is a non-inverted polarity and the first offset signal is a negative voltage.
4. The method of claim 1 , wherein the plurality of digital differential signals comprises a plurality of digital differential signals received in accordance with an RS-485 or RS-422 data transmission protocol.
5. The method of claim 1 , wherein the receiving the plurality of digital differential signals further comprises receiving the plurality of digital differential signals including a negative offset signal on at least one input of a comparator, if a polarity of the plurality of digital differential signals is an inverted polarity.
6. The method of claim 1 , wherein the receiving the plurality of digital differential signals further comprises receiving the plurality of digital differential signals including a positive offset signal on at least one input of a comparator, if the polarity of the plurality of digital differential signals is an inverted polarity.
7. The method of claim 1 , further comprising:
a receiver in an idle state outputting a logic high signal if the control signal has indicates the first polarity or the second polarity, and thereby attaining the full fail-safe function in the receiver if a plurality of digital differential inputs of the receiver are open or floating, shorted together, or shorted with a termination resistor.
8. A method of providing a full fail-safe transmission capability, comprising:
receiving a plurality of signals on a plurality of inputs;
coupling a first input of the plurality of inputs to a plurality of offset signal generating units;
if a polarity of the plurality of signals is a first polarity, selecting a first offset signal generating unit of the plurality of offset signal generating units and thereby adding a first offset signal to the plurality of signals received at the first input;
if the polarity of the plurality of signals is a second polarity, selecting a second offset signal generating unit of the plurality of offset signal generating units and thereby adding a second offset signal to the plurality of signals received at the first input, wherein the first offset signal and the second offset signal have opposite polarities; and
outputting a logic signal representing an idle state, if the plurality of inputs are open or floating, shorted together, or shorted with a termination resistor.
9. The method of claim 8 , wherein the first polarity is an inverted polarity and the first offset signal is a positive voltage.
10. The method of claim 8 , wherein the second polarity is a non-inverted polarity and the second offset signal is a negative voltage.
11. The method of claim 8 , further comprising: performing the receiving the plurality of digital differential signals and the control signal and adding the first offset signal and the second offset signal in an Integrated Circuit (IC).