User manual

NIC Setup and Testing
31
Maximum of 32 devices
with a
total cable length of
4000 feet.
Modbus RTU Master
EIA-485 9600,N,8,1
R
Maximum of 32 devices
with a
total cable length of
4000 feet.
R
Maximum of 32 devices
with a
total cable length of
4000 feet.
Figure 10. Exceeding Maximum Specifications
The maximum specification may be exceeded if measures are
taken to drive or boost the EIA-485 communication line. Two
wire EIA485 repeaters are available through the Liebert
Corpration. SiteScan’s “REPOPT” will work sufficiently for
this application. Consult the SiteScan price book for pricing
schedule and alternative solutions.
MODBUS SLAVE FUNCTIONS
Data Type
The OpenComms NIC supports data in a register block as one of
the following types: Signed integer (16 bit) / Unsigned integer
(16 bit) / Signed long (32 bit); IEEE floating-point (32 bit); Null
terminated String.