Brother MFC4550 PLUS - Manual (Page 164)

If necessary, set the serial interface parameters as follows:
1. Make sure the printer is in offline.
Table 1; Serial Interface Parameters Settings Table 2: Baud Rate Settings
Selector Parameters On (up) Off (down) Selector 1 Selector 2 For ES-422A For ES-232C
1 Band Rate — See Table 2. — . Off Off 57600 9600
2 Baud Rate — See Table 2. — On Off 9600 4800
3 Data Length 7 bits 8 bits Off On 1200 1200
4 Stop Bit 2 bits Ibit On On 19200 19200
Parity - See Table 3.
Parity — See Table 3.
Protocol Xon/Xoff+DTR DTRonly Table 3: Parity Settings
Robust Xon On Off
Selector 1 Selector 2 Parity
On On Odd
On Off Even
Off None
The factory settings are indicated in bold print.
If the robust Xon setting is turned on with selector 8, the printer sends Xon signals at one
second intervals to the connected computer until it receives data. It is effective only if
selector 7 is set to the On position for the Xon/Xoff plus DTR setting.
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