ASG Tech Note: Connecting and Communicating with DSA
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4. Using the recommended B&B Electronics USB-485 Converter:
The B&B Electronics USPTL4-LS converter has been thoroughly tested for compatibility with
DSA, both for overall control and to update firmware. The converter includes a thorough ‘Quick
Start Guide’, which guides the user through software installation. EAW stocks these converters
(EAW model name ACC-USB485DSA, part number 2040889).
Note: It is critical that you install the USPTL4-LS software
prior
to initial connection to the
computer’s USB port. Follow steps #1-3 of the USPTL4-LS Quick Start Guide. Note the COM port
to which the USB-485 adapter is mapped.
Ensure the converter’s dip switches (located on the underside of the unit) are configured as
follows:
Switch Correct
Orientation
Setting
1 On/Right
RS-485
2 On/Right
ECHO
OFF
3 On/Right
2-Wire
4 On/Right
2-Wire
Wire the converter’s terminals as follows:
Terminal Connected
To
Purpose
TDA(-) Not
Connected
Unused
TDA(+) Not
Connected
Unused
RDA(-)
DSA RS-485 Negative (-)
Data A Input/Output
RDB(+)
DSA RS-485 Positive (+)
Data B Input/Output
GND DSA
RS-485
Ground
Ground
On the DSA, ensure that the “EIA-485 Terminate” switch is in the “On” position for the
last
DSA in
the RS-485 chain (farthest from the computer). If only one DSA is connected to the computer, this
switch should be in the “On” position.
