INSTALLATION MANUAL User Manual

Chapter 5

Serial Communications

5–7

Clearing Lines of Text

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• You can either send a message packet with a control byte (field 1) that has

a Ctrl-C (decimal 3) value, or

• You can send a message packet with the following format:

Slave Address

Field 1

1 Byte

Line Number

Field 2

1 Byte

Carriage Return

Field 3

1 Byte

The line number in the message packet specifies which line(s) to clear:

ASCII Character Decimal Value Function

Ctrl-A 1 Clear line 1.

Ctrl-B 2 Clear line 2.

2 50 Clear all lines.

Performance

The DL50 display requires a time delay between successive packets sent

from the host (master) to the DL50 display. This delay is referred to as the

“inter-packet delay”. It is required so the DL50 can process the received data

properly before the next packet is received.

These delays need to be programmed into the host system only if messages

will be sent in rapid succession to the same display. The time delay interval

required is a function of the display type, character size, baud rate, and

packet length. Table 5.F lists the required delay times for DL50 displays

operating in Simplex Protocol mode, using the worst case scenario.

Table 5.F

Simplex Protocol Inter-Packet Delay Requirements

19200 Baud with Large Characters (worst case)

Display Type Packet Length Delay (milliseconds)

2706-F11J 250 characters 300 mS

2706-F11JC 250 characters 350 mS

2706-F21J 250 characters 300 mS

2706-F21JC 250 characters 350 mS

Note: Typical inter-packet delay requirements for most applications range

from 80 to 250 milliseconds.

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