Instruction manual

SECTION 5. STG MODULE: SMS - STORAGE MODULE SOFTWARE
PC208W, Version 3.0, Instruction Manual 5-3
5.2.2 ESTABLISHING COMMUNICATIONS
For storage modules, the first step is to establish
communications between your storage device
and the computer. This involves selecting the
correct communication port and baud rate for the
device being used from the SETUP screen.
If you have a computer fitted with a correctly
configured card reader you can set it up for use
with SMS. This is accomplished by going to the
PC CARD SETUP screen, and clicking the
Setup PC Card button. When you click this
button you will be guided through the correct
setup procedure and the optimum software
drivers will be used to establish
communications (usually via socket 0).
NOTE: The PC Card drivers are NOT set
up automatically, and should be set up as
described above. Even if you are already
using PC Cards successfully with your PC,
it is recommended that you use the setup
facility provided for use with SMS.
The following paragraphs in this section are
applicable for Campbell Scientific’s external
Solid State Storage Modules.
Selecting a COM Port
For an externally connected storage device you
can use one of your computer’s Communication
(COM) ports for connecting the storage module
to the computer. The first time that you connect
a module to your PC a default port of COM1 is
automatically selected. If this is the port to which
you have connected your module you can
proceed to select the BAUD rate as explained
below. If you are not using COM1 for connection,
you will need to select the port being used by
clicking on the appropriate checkbox in the Port
Selection box. This will be COM1 or COM2 for
most computers, but SMS can use COM3 and
COM4 if your computer is equipped with these.
The physical implementation of the COM port is
hidden from the software. The Windows
environment provides a common interface via a
COM port driver, with which SMS
communicates. Sometimes, however, you might
have a COM port which shares interrupts with
other COM ports. This can be checked by
examining the “Ports” (Settings/Advanced)
setting in the Windows Control Panel. A COM
port sharing an interrupt with another device
can prevent Windows from performing high-
speed communications using that port. This
shared interrupt problem would, therefore, also
affect operation of SMS.
NOTE: If you appear to be experiencing
communication problems when using
external modules, always check the COM
ports setting in the Windows Control Panel,
using the “Ports” (Settings/Advanced)
option, and check for any shared interrupts.
Baud Rate
The first time you use SMS with a storage
module a default baud rate of 38,400bps and
19,200bps is automatically selected for the
CSM1/MCR1 and SM192/716 modules,
respectively.
The default (maximum) baud rate (38,400bps
for CSM1/MCR1 and 19,200 for SM192/716)
can be adjusted to your own requirements,
depending on, among other things, the speed of
your COM port and processor speed.
When SMS reads data from the storage device,
it automatically performs a checksum test and
requests that bad data be re-transmitted. To
signify when bad data is detected, the computer
will beep.
When communication errors occur, it may help
if you reduce the baud rate. Possible reasons
why good communications cannot be
established using higher baud rates under
Windows are:
• Using cheaper low-quality cards, or using
cards but with generic drivers rather than
the hardware specific drivers.
• Processor is loaded down by other
applications (e.g., DOS programs set to
exclusive mode or other operating Window
communication programs).
• A computer without a buffered UART
(Universal Asynchronous Receive/Transmit)
serial port (e.g., a 16550 UART), or without
the FIFO (First In First Out) option enabled.
(Other communications problems can occur
if the computer does not actually have a
buffered UART, but is using the Windows
95 default configuration with the FIFO
option enabled.)