KEPCO MBT Series - Manual (Page 92)

3-54
MBTSVC111609
FIGURE 3-3. RS 232 IMPLEMENTATION
Only four control characters (characters between 00
H
and 1F
H
) are acknowledged by the power
supply:
• Carriage Return (CR, 0D
H
)
• Line Feed (LF, 0A
H
)
• Back Space (BS, 08
H
)
• Escape (ESC, 01B
H
)
BS deletes the last character entered, with the exception of CR or LF characters. Either the CR
or LF character acts as the line terminator, initiating parsing of the ASCII data sent to the MBT-G
power supply by the command originator. When the line is parsed and the commands are sent
to the individual power supplies via the IEEE 1118 bus, the MBT-G power supply sends the line
terminator sequence CR LF to the command originator.
The ESC character is used for synchronization, causing the MBT-G to reset its input buffer and
return a CR LF sequence.
All non-control characters are sent via the serial port of the command originator. The control
character BS is echoed as BS Space BS. Only the first control character is returned in response
to either a CR LF or LF CR character sequence (see Figure 3-3).
3.3.3.2 ECHO MODE
Echo mode is the default method of ensuring data is transferred without errors. Each byte (char-
acter) is echoed back to the sender where it is verified as the same character that was just sent.
If the character is incorrect or missing, the sender sends the character again until the correct
character is verified as having been received.
All non-control characters are sent via the serial port of the command originator. The control
character BS is echoed as BS Space BS. Only the first control character is returned in response
to either a CR LF or LF CR character sequence (see Figure 3-3).
3.3.3.3 PROMPT METHOD
The command originator sends a message line (command) to the MBT-G and waits until the
prompt sequence CR LF > (3E
H
, 62
10
) is received. The MBT-G sends the prompt sequence CR
LF > to the command originator indicating the power supply is ready to receive the next com-