Function key ascii strings, Displaying predefined messages using function keys – Maple Systems STEPware-100 User Manual

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ENTER key - this action allows the function key to behave as an ENTER key, enabling the

OIT operator to send a line terminator to the host and perform other actions when the OIT

is in Block or Network mode. This action is only available on OIT models that do not have

a predefined ENTER key, (such as the OIT3100 and OIT4100 Series). The ENTER key

will behave differently according to the operating mode used. Refer to Chapter 3:

Operating Modes for more information.

CLEAR key - this action allows the function key to behave as a CLEAR key, enabling the

OIT operator to send a line terminator to the host and perform other actions when the OIT

is in Block or Network mode. This action is only available on OIT models that do not have

a predefined ENTER key, (such as the OIT3100 and OIT4100 Series). The ENTER key

will behave differently according to the operating mode used. Refer to Chapter 3:

Operating Modes for more information.

Function Key ASCII Strings

Two ASCII text strings can be created and assigned to each function key. Two strings

provide the function key with the ability to simulate a momentary or on/off switch or

provide two selections when the function key is configured as a shifted function key.

Each string can contain up to 40 ASCII characters including control characters. The two

ASCII strings are referred to as the Key ON (Unshifted) Message and the Key OFF

(Shifted) Message. These strings are sent to the host according to what action the

function key is configured as (see above). These strings are also sent to the OIT display

if the following conditions are met:

Interactive Mode:

1. Local Echo option is enabled
2. Send Message to Host Only option is disabled
3. Display Message option is not used

Block or Network Mode:

1. Block Echo is enabled
2. Display Message option is not used

Displaying Predefined Messages using Function Keys

The predefined messages that are created on the main screen of the STEPware-100

configuration software are stored in the OIT and can be displayed on the OIT screen

either through a control command call from the host computer (refer to Appendix A:

Control Commands) or by configuring the function keys to display the message.

Although the OIT can store up to 500 messages, each function key is limited to

displaying Messages #1-60.
The feature allows the OIT operator to send an ASCII string to the host while displaying

one of the predefined messages on the OIT that may describe the action just taken. This

feature is particularly useful when the ASCII string sent to the host is a command that is

not displayable on the OIT screen (because it contains mostly control characters that

cannot be represented on the OIT screen). For instance, a command is sent from one of

the function keys to stop a motor:

ESC

1E S 0

CR

. Instead of displaying the command

sent to the host, (which doesn’t mean anything to the OIT operator), a message is

displayed on the OIT screen which says, “Motor has been stopped!”. This helps

provide the OIT operator with confirmation that the key he has pressed has performed an

action.

48

STEP1 Protocol Operation Manual

1010-0096, Rev. 04

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