The READ ASCII MESSAGE command is used to start running a read message on the module, that is, taking ASCII characters from the input/receive buffer of a serial port to fulfil the variable formats of the message. All output only formats still send ASCII characters to the serial port.

In addition to starting a message, this command is capable of transferring up to nine registers of data from the module to the controller after the message has completed (this is the data count). The data returned is gotten from the starting register number provided in Command Word 1.

This command is executed only the first time it is received. To execute the command again, Command Words 0, 1, or 2 need to be changed. This is done so that the same message does not get continuously run until Command Word 0 changes to a command other than READ ASCII MESSAGE.