Item Tag; Read/Write Data (R/W) - Johnson Controls XP-910x Configuration Manual

Item Tag

Read/Write Data
(R/W)
24 Configuration Guides—XT-9100 Configuration Guide
3. Totalized Numerical Items are actual positive numbers. They refer
to totalized values of pulse counters. They are displayed and entered
as whole numbers, without a sign or decimal point. These Items are
shown in the Item List with "4 Bytes" in the Type column.
4. Status Items are either 1-byte or 2-byte Items giving information on
the actual status or configuration of the inputs, outputs and modules,
where each bit has a specific meaning as described in the Item List.
These Items are shown in the Item List with the number of bytes in
the Type column. Data is displayed and entered as bytes. In the list
the bytes will be represented using X1-X8 or X1-X16.
1 Byte = X8 X7 X6 X5 X4 X3 X2 X1
2 Bytes = X16 X15 X14 X13 X12 X11 X10 X9 X8 X7 X6 X5 X4 X3 X2 X1
Each Item in the Item List has a unique name or "tag," which summarizes
the description and the meaning of the data which is stored in the XT-9100
memory.
The Items are shown in the Item List with their respective names in the
Tag column.
The Items shown in the Item List can be divided into three basic
categories:
1. Input values and status of the XT-9100 can be read but not changed
by a Supervisory System. These Items are shown in the Item List
with an "R" in the R/W column.
2. Variables in the XT-9100 can be read and modified by the GX-9100
Graphic Configuration Software or Supervisory System. These Items
are shown in the Item List with an "R/W" in the R/W (read/write)
column. (E) indicates that the Item is stored in EEPROM.
3. All other Items in the XT-9100 refer to configuration parameters of
the controller and contain information such as analog ranges, output
type, etc., and they can only be changed with the GX-9100 Graphic
Configuration Software. These Items are shown in the Item List with
a "CNF" (configuration) in the R/W column.
All Items can be accessed by the SX Tool via a DX-9100 Controller.