Principles of Operation: Notes

The message center electronic functions use both hardwired, standard corporate protocol (SCP), and the universal asynchronous receiver-transmitter (UART)-based protocol (UBP) communication networks to transmit and receive information. It is very important to understand:

• where the input (command) originates from.
• all the information (messages) necessary in order for a feature to operate.
• which module(s) receive(s) the input or command message.
• does the module which received the input (message) control the output of the feature, or does it output a message over the SCP or UBP communication network to another module?
• which module controls the output of the feature.

  The message center provides the following features:

• information displays
• setup displays
• warning messages
• system check messages

  The message center information can be selected through a set of three switches:

• INFO
• SETUP
• RESET