Galvanic Applied Sciences ProTech903, Operation Manual

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Revision 14
120 August 02, 2019
Figure 5-36: Create Modbus List Dialog Box
The dialog box gives the choice of the 3 possible types of Modbus. Select the desired type of
Modbus list and press OK . When a new Modbus list is opened, one of three possible empty
trees appears in the main Modbus window, depending on the type of Modbus chosen. The
three possible Modbus trees are shown in Figure 5-35.
Figure 5-37: Empty Modbus Trees
The
Enron
tree is at left, the
Modicon 16
tree is in the centre, and the
Modicon with Floating
Point
tree is at the right. The number in brackets after each node label indicates how many
data points are in each node.
At the bottom of the screen are two fields. One is entitled
Modbus Type
and tells the user
what type of Modbus list currently open. Note that the value in this field for Modicon with
Floating Point will read MODICON32. The other field is called Address, and the user must
input the desired Modbus address for the analyzer into this field.
5.16.1 Enron
An
Enron
Modbus list contains 4 nodes on the Modbus tree. They are
Coils, Short Integers,
Long Integers,
and
Floating Point
. Coils are Boolean data points – that is to say, they have a
value of either 0 or 1. To that end, data points entered into the Coils node would usually be
data points that are simple status indicators, indicating the status of a given alarm, input, or
output. If the value of the data point is 0, the status of the logged alarm, relay, etc, would be
off, and if the value is 1, the status would be on. Short integers are 16 bit whole numbers with
either positive or negative sign. Long integers are 32 bit whole numbers with either positive or
negative sign. Floating point values are also 32 bit numbers, but unlike the integers they do
not have a dedicated sign bit., but they do have decimal points.