Register monitors – Maple Systems OIT Family (ASCII) User Manual

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Register Monitors

The OIT’s data and coil registers can be monitored, displayed, and updated by the OIT. This

is done by configuring the OIT screens to display OIT data and coil registers as embedded

data fields (register monitors). When the OIT displays a screen that contains a register moni-

tor, the OIT reads the specified OIT register address and then displays the data. If the register

monitor has been configured as read/write, when the OIT operator changes the data in the

If the “Notify Host of Read/Write Register Monitor Updates” feature is enabled, the OIT

also notifies the ASCII host of the new value.

A maximum of 25 register monitors can be displayed on each screen. If more than one regis-

ter monitor is on a screen, each register monitor is updated by the OIT in continuous succes-

sion as rapidly as possible. Therefore, the update rate of each register monitor is determined

by the number of register monitors on the screen.

The Arrow keys move the cursor from one read/write register monitor to another. Each time

one of the Arrow keys is pressed, the cursor moves to the next closest read/write register

monitor in the direction of the pressed Arrow key. When the cursor is located at one of the

edges of the display, additional keypresses in the direction of the display edge will cause the

cursor to wrap around, from top to bottom, etc.

Once the cursor is positioned in the correct register monitor, the OIT operator can press the

Clear key to clear the current register monitor’s contents and activate data entry mode. The

The OIT operator can now enter a new value using the numeric keys or the Delta+ and Delta-

keys on the OIT’s keypad. Once the correct value has been entered, the OIT operator should

press the Enter key. If the value is within the preset upper and lower limits, the entry is ac-

cepted and immediately written to the OIT register address. If the “Notify Host of

Read/Write Register Monitor Updates” feature is enabled, the OIT also notifies the ASCII

host of the new value. If the value is outside the preset upper and lower limits, an error mes-

sage is displayed indicating that the value entered is out of range.

Note: When the OIT operator enters data into a register monitor that has the adjustable

decimal point enabled, the OIT operator does NOT enter the decimal point, but simply

enters the raw number. Once the data has been sent to the OIT register address, the

correct decimal position will be shown.

Notify Host of Read/Write Register Monitor Updates

By default, if the OIT operator changes the value in an OIT data register using a read/write reg-

ister monitor, the ASCII host does not know the value changed until the ASCII host reads that

particular OIT data register using the Read control command. In most cases, this is acceptable.

However, the ASCII host may need to know about the change in value immediately.

Therefore, the OIT can be programmed to notify the ASCII host of any changes to the data

values which reside in the OIT’s data registers that are made by the OIT. When the “Notify

Host of Read/Write Register Monitor Updates” feature is enabled, the OIT sends the new

value to the ASCII host whenever an OIT data register is changed by the OIT. When this fea-

ture is enabled, the ASCII host does not have to poll all of the OIT’s data registers in order to

determine if a change has been made to any of the data registers by the OIT.

FEATURES

1010-0088, REV02