Slow File Transfer; Losing Data - Multitech MULTIMODEM MT5600ZDX Owner's Manual

Slow File Transfer

• You may have an older UART. For best throughput, install a
16550AFN UART or a Multi-Tech ISI serial port card.
• If you are running under Windows 3.1 and have a 16550AFN
UART, you must replace the Windows serial driver, COMM.DRV,
to take full advantage of the UART's speed.
• If you are using a slow transfer protocol, such as Xmodem or
Kermit, try Zmodem or Ymodem/G instead.
• Is your line noisy? If there is static on your line, the modem has to
resend many blocks of data to insure accuracy. You must have a
clean line for maximum speed.
• Are you downloading a compressed file with MNP 5 hardware
compression enabled? Since hardware data compression cannot
compress a file already compressed by an archiving program, the
transfer can be marginally slower with data compression enabled
than with it disabled.
Try entering the &V (View Parameters) command, making a
•
screen print of the diagnostics listing, and checking for parameters
that may be unacceptable.

Losing Data

• If you are using data compression and a high speed serial port,
set the serial port baud rate to four times the data rate.
• Your UART may not be reliable at serial port speeds over 9600
bps or 19,200 bps. Turn off data compression, reset your serial
port speed to a lower rate, or replace your serial port with a faster
one.
• Make sure the flow control method you selected in software
matches the method selected in the modem.
• If you are running under Windows 3.1 and have a 16550AFN
UART, you may need to turn on the 16550's data buffers and/or
replace the Windows serial driver, COMM.DRV.
• Try entering the &V (View Parameters) command, making a
screen print of the diagnostics listing, and checking for parameters
that may be unacceptable.
Chapter 2 - Installation
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