Design Analysis H-350XL, Owner'S Manual

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6-4 Serial Port Options
XL™ Series
used as a binary checksum value is calculated for each block of data and transferred with the data
block. If the binary checksum value is the same as an XOFF command, then the system may stop
the data transfer prematurely.
Hardware flow control uses two extra pins on the 9 pin connector. This is ‘Request to Send’
(RTS) and ‘Clear to Send’ (CTS). Normally a PC connected to the XL™ will turn on the CTS
signal when it is ready to communicate and watches the RTS signal before it sends anything to
the XL™. The same type of monitoring will be done by the XL™, It will not send anything to the
PC if CTS is not on and will turn on RTS indicating to the PC it is ready.
NOTE: Hardware flow control should only be enabled on the PC when the XL™ is turned on. If
hardware flow control is enabled on the PC and the XL™ is off, the PC will not be able to turn
on the XL™ because the PC will wait for the RTS signal to go active before sending the wake up
characters, and RTS will only go active when the XL™ is turned on over the serial port.
PC Interface View Built In Display Screen
C - Character Delay: 000
Char Delay [000]
This sets a time delay between transmitted characters in milliseconds. Some modems, normally a
radio modem, may require this type of control in order to pass valid data through the serial port.
When using a modem everything may look fine and then all at once it looks like garbage. This
may be an indication of overflowing a buffer in the modem and it was not able to warn the XL™
soon enough to prevent the problem and the data becomes junk. Try setting the character delay at
005 and then working up as needed. A combination of a character delay and the line delay may
provide the best system operation. The default is 0.
NOTE: This only applies to com port 1 at this time.
PC Interface View Built In Display Screen
L - Line Delay: 000
Line Delay [000]
This is a delay used at the end of each line of data sent out the active serial port. This is in
milliseconds. This used in combination with the character delay may be required by some modem
applications. The default is 0 indicating no delay.
PC Interface View Built In Display Screen
T - Terminal Emulation: VT-100
Emulation [VT-100]
Terminal emulation is used to control computer screen operations like clearing the screen or