Communications With The Host; Direct Connection Function - Omron NT631 Series Reference Manual

Communications with the Host

1-4

Communications with the Host

1-4-1 Direct Connection Function

Features of the Direct
Connection Function
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The NT31/NT31C or NT631/NT631C is connected to the host by one of the fol-
lowing four communication methods.
The following communications can be used to connect an OMRON PC:
• Host link
• 1:1 NT Link
• 1:N NT Link (standard or high-speed)
The following communications can be used to connect another companies' PC
or FA computer:
• Communications protocol supported by the other company's PC
• Memory link
In all of these communication methods that can be used with NT31/NT31C or
NT631/NT631C, data communication with host is by direct connection (Memory
link is, however, a quasi-direct connection).
In the following, the host link and NT Link that carry out the direct connection will
be discussed. Memory link will be explained in section 1-5 Communication by
Memory Link .
With the NT31/NT31C or NT631/NT631C, the bits and words referring to data
required for display, and those for storing input data, can be allocated to any part
of the PC memory area.
The NT31/NT31C or NT631/NT631C can directly write to and read from such
allocated bits and words to change the display status of the elements on the PT
screen, control the PT operating status, and notify statuses to the host.
This function, which directly reads and writes the statuses of words and bits with-
out using a PC program is called the direct connection function.
The words and bits allocated for direct connection are called the allocated words
and allocated bits.
The direct connection function allows the data to be displayed at the PT to be
read from the memory area in the PC and written to memory tables in the PT.
Also, the data input at the PT can be written to the memory area in the PC. The
PT screen can be changed in accordance with statuses in the PC memory area,
and the PT's status data can be written to the PC's memory area.
PT
The direct connection function has the following features.
• The bits and words referring to operating status and work instruction informa-
tion and those for storing input data can be freely allocated to almost any area
of the PC memory.
• Since the PT can directly refer to PC bit and word data without using the pro-
gram at the PC, it can be connected to the PC without changing the PC pro-
gram which controls the currently running production line.
• The area to control and notify the PT statuses, including display screens, dis-
play/no display status, and buzzer output, can be freely allocated to any part of
Section
PC
DM area I/O relay area
Auxiliary relay area Timers/counters
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