Omron NT15S, Operation Manual

Page: 189 / 233

175
Standard Mode
Section 4-26
4.23.6 Refreshing the Message System
The following hex code can be used from the controller to cause the operating
terminal to read in the most recent parallel messages.
This procedure can be used to achieve an event-controlled message system.
Hexadecimal code: 7FFF
H
4.24 Cyclic Variables
The term Cyclic Variables refers to data which may change continuously while a
mask is displayed, i.e. all types of ACTUAL VALUES. The terminal must therefore
poll the controller for the current values at cyclic intervals. The time selected here
specifies the intervals at which these mask values are refreshed.
In addition to the cyclic variables, the terminal also polls the controller for the cur-
rent status of the Write coordination byte, the serial message channel and the
LEDs (update). This process is either time or event controlled depending on the
protocol. No polling will take place if the value = 0 is entered for the time period. If
this variable is not polled, then an external control of the data release is not pos-
sible, for example.
4.25 Interface Parameters
The interface parameters selected in the programming system are stored in the
mask memory. It is, however, possible to modify the data in the operating terminal
at a later date. Values modified in the operating terminal are retained in the battery-
backed RAM. When necessary, the original settings can be restored at any time.
The parameters of the interface channel SER1 are determined by the protocol.
Modifications to any of these parameters could result in communication failures.
Values that are not typical are detected when the terminal is initialized and a mess-
age to this effect is generated.
The parameters of the interface channel SER2 are reserved for control of a printer
and, when transferring data. This process requires that the settings for both de-
vices must match. The selected parameters do not apply to the download. For the
download, the system will automatically switch to the highest possible transmission
rate.
4.26 Variable Definition
The variable definition contained in the user description defines the format, type,
range of values, scaling and attribute of the representation. All controller-independ-
ent parameters are stored here. For editable variables, it is additionally possible to
influence the Editor and the transfer mode to the controller. The variable definition
contains the symbolic name of the variables, the format definition and, if necessary,
the text lists in the case of selection text variables.