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Device
number simply shows you where you are on the device list. Click
"next" and "prev" to scroll through the list.
Remote
Modbus/TCP devices to be accessed by this device are specified here.
Enter the IP address of the remote device, a name to reference in
other pages, a unit number, poll rate, and check "swapped" if
appropriate. Then click "update".
The
term "swapped" only applies to double or float formats. Modbus
registers are, by definition, 16 bits of data per register. Access to
32-bit data, either 32-bit integer ("double"), or IEEE 754 floating
point ("float"), is supported by the use of two consecutive
registers. Modbus protocol is inherently "big endian", therefore, Modbus
by the Module defaults to having the high order register first for
double and float. If the low order register comes first on the device
being accessed, check the "swapped" box.
If you have
"swapped" turned around, you will quickly recognize it. If floating
point data is reversed, a 1.0 becomes 2.2779508e-41, which simply rounds
to zero. The pattern is not as predictable as the 1.0 example would
suggest. A floating point 1.1 becomes negative 107609184. If 32-bit
integer data is reversed, 1 becomes 65536.
Connection
status will show a non-zero error code if there is a socket error.
Possible errors include:
-104
Connection reset by peer -111 Connection refused -113 Connection
aborted -114 Network is unreachable -116 Connection timed
out -118 Host is unreachable -119 Connection in progress (means
unsuccessful connect attempt, still trying)
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