How to Disable RS232 Autobaud for ACR9XXX

Products: ACR9000, 9030,9040,9600,9630,9640

By default the COM1 port of the ACR9000 controllers will auto-detect the baud rate of the connecting device. The baud rate is detected upon receiving 2 carriage return characters (0x0D) spaced more than 50ms apart. In some applications it may be helpful to disable the auto baud detection. This is accomplished by setting parameter P7013 using the tables below.

NOTE; after setting P7013= to a value, issue the ESAVE command.

for common settings of 8 data bits, 1 stop bit, no parity and the following baud rates, set P7013 to the values from this table.

Baud	P7013
2400	33544
4800	33552
9600	33568
19200	33600
38400	33664

For any other settings, use this table

Baud rate Field Selection	Bit Index	Selects the baud rate when the Autobaud Detect function is disabled. The baud rate field is set as follows: Baud rate Bit 7 thru Bit 0 = Baud rate / 300 For Example: To select a baud rate of 9600: 9600 / 300 = 32 2400 (+8) 4800 (+16) 9600 (+32) 19200 (+64) 38400 (+128)
Bit Description	Bit Index
Baud rate Bit 0	0
Baud Rate Bit 1	1
Baud Rate Bit 2	2
Baud Rate Bit 3	3
Baud Rate Bit 4	4
Baud Rate Bit 5	5
Baud Rate Bit 6	6
Baud Rate Bit 7	7
Data bits Control Fields		Selects the number of data bits transmitted as follows: 0 = 5 Data Bits (+0) 1 = 6 Data Bits (+256) 2 = 7 Data Bits (+512) 3 = 8 Data Bits (+768)
Data bits Bit 0	8
Data bits Bit 1	9
Stop bits Control Fields		Selects the number of stop bits as follows: 0 = 1 Stop Bit (+0) 1 = 2 Stop Bits (+1024)
Stop bits	10
Parity Bits Control Fields		Selects the parity as follows: 0 = No Parity (+0) 1 = Odd Parity (+2048) 2 = No Parity (+4096) 3 = Even Parity (+6144)
Parity Bit 0	11
Parity Bit 1	12
Reserved	13
Reserved	14
Startup Enable Control Fields		Enables / disables the Autobaud Detect feature 0 = Enable autobaud detect 1 = Disables autobaud detect (+32768)
Startup Enable	15

23-mar-2012 jw