Off topic : RS232 control lines

[TL]

The RS232 TX and RX lines go through 2 RS232 chips (e.g MAX232) for data communication between 2 pieces of equipment. Can someone tell me whether the control lines such as RTS and CTS need to go through these chips as well?

Thanks.

[asmallri]

Yes they are also intended to go thru the transceivers. The max232 chip includes two pairs of transceivers which could be used for this purpose.
_________________
Regards, Andrew

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[rnielsen]

You need to remember that ALL standard RS232 signals are at +12v to -12v (granted, some are just +10v to -10v). They All need to be converted to TTL levels for the PIC to use them and for the PIC to send them out to the RS232 line. Otherwise, the PIC could have some sort of electron worker rebellion and the Coulomb union would have them all going on strike due to over-stressed working conditions. The electron workers will end up rioting and burning everything in sight. And, once you see all of the smoke from those fires the union will never allow the electrons to work there again.

Ronald

[asmallri]

RS232 is valid down to at +3volts and -3volts
_________________
Regards, Andrew

http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!!

[Ttelmah]

Not technically at the 'source'.
The requirements at the 'driver', are between +5v, and +15v for the 'space', into a load between 3KR, and 7KR. The 'mark' is -5 to -15v into the same load. At the receive end, the signal can be as low as +/-3v, or as high as +/-25v. With no load, the drive voltages are allowed to go as high as the +/-25v.
A lot of drivers now 'bend the rules', and only output perhaps 4v, which with short wiring will still meet the receive level requirements, but will not give the range specified in the RS232 spec, for a given baud rate.

Best Wishes