SERRXD (qualifier,qualifier...)

SERRXD (qualifier,qualifier...),{#}variable,{#}variable...

SERRXD {#}variable,{#}variable...

Additional optional timeout syntax options for M2, X1 and X2 parts

SERRXD [timeout], (qualifier...)

SERRXD [timeout], (qualifier...),{#}variable,{#}variable

SERRXD [timeout], {#}variable,{#}variable

SERRXD [timeout,address], (qualifier...)

SERRXD [timeout,address], (qualifier...),{#}variable,{#}variable

SERRXD [timeout,address], {#}variable,{#}variable

Qualifiers - are optional variables/constants (0-255) which must be received in exact order before subsequent bytes can be received and stored in variables.

Variable(s) - receive the result(s) (0-255). Optional #'s are for inputting ASCII decimal numbers into variables, rather than raw characters.

Timeout - is an optional variables/constants which sets the timeout period in milliseconds (not available on M parts).

Address - is a label which specifies where to go if a timeout occurs.

Serial input via the serial input programming pin (at fixed baud rate 4800 (9600 on X2 parts), 8 data, no parity, 1 stop).

The serrxd command is similar to the serin command, but acts via the serial input pin rather than a general input pin. This allows data to be received from the computer via the programming cable. The PICAXE chip normally constantly scans the serial download pin to see if a computer is trying to initialise a new program download. However when it is desired to use serrxd it is necessary to disable this scanning. This is automatic, and is effectively the same as issuing a disconnect command.

After disconnect is used it will not be possible to download a new program until:

1) the reconnect command is issued

2) a reset command is issued

3) a hardware reset is carried out.

Remember that is always possible to carry out a new download by carrying out the hard-reset procedure.

Reading number values

When the #variable format is used received data will be taken and converted to a number.

All characters received are ignored until the first ASCII digit character is received. A number is then determined until a non-digit character is received. The value stored in the variable will be number represented by the digit characters received. Note that the #variable will not complete until the number has been terminated by a non-digit character being received.

Effect of Increased Clock Speed

Increasing the clock speed increases the serial baud rate as shown below (non X2 parts).