Modbus Plus X-Link Driver User’s Guide
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3.1 Configuration Parameters
The Modbus Plus driver is distributed in the file SA85.DRV. Once the
SA85.DRV is loaded into the X-Link, the following parameters are required:
Card Segment The memory address for the SA85 card. The card requires 2K
of memory in the range of C000 to EF80. Default is D000,
second choice is D800.
Convert Floats With this option is on, the Modbus Plus Driver will convert the
data types between the integer supported by the Modbus Plus,
and floating points stored in the X-Link. Incoming integers will
be expanded to floats; the floats written to the Modbus Plus will
be truncated. When this option is off, the floating points will be
read and written as two consecutive integers. Default option is
Off.
Poll Rate Because the driver does not use interrupt settings, it must
access data from the card at a certain rate. The poll rate ranges
from 2 ms to 255 ms with a default of 10 ms.
The memory address selected must match the switch settings on the SA85.
The memory base address switches are located near the bus connector on the
SA85 and are not accessible from the outside of the X-Link.
The Modbus Plus node address must also be set on the SA85. The switches
to set the station address are accessible from the end of the X-Link.