Overview - Omron C200H-ASC11 Manual

Overview

1-1 Overview
ASCII Communications
with Peripheral Devices
Multiport
Communications
Special Processing
C200H-ASC11/ASC21/ASC31 Features
High-capacity User
Memory
High-speed Processing
RS-422A/485 Port
Various Formats for
CPU Unit Data Transfers
2
The ASCII Unit is a Special I/O Unit that can exchange ASCII data with per-
sonal computers, board computers, bar code readers, ID systems, and non-
OMRON Programmable Controllers (PCs) via an RS-232C or RS-422A/485
interface. Because it is programmed in BASIC, the ASCII Unit can indepen-
dently process read/write data from general-purpose peripheral devices, mak-
ing it easy to combine sequence control and information processing on the
same PC.
The following functions are provided. These functions are not possible with
protocol macros and host link non-procedural communications alone.
• Flexible processing of character strings (sampling, comparison, combina-
tion, and length determination of portions of character strings).
• Reception processing for only a portion of the data from a receive buffer.
• Processing of interrupt subroutines, such as those for communications,
time processing, and PC interrupts.
• Flexible response processing, such as retries and time monitoring.
These functions enable the ASCII Unit to handle all kinds of communications
frames and protocols. It can handle essentially all data exchanges with other
devices equipped with an RS-232C or RS-422A/485 port.
Up to either 10 or 16 ASCII Units can be mounted on each PC (depending on
the model of the CPU Unit), making ASCII Units ideal for monitoring a large
number of general-purpose peripheral devices via communications.
Apart from communicating with general-purpose peripheral devices, ASCII
Units can also be used for special operations. Data operations, character
string processing, logic flow processing, and other operations that are difficult
to carry out in the PC can be handled by using the ASCII Units as "sub-CPUs"
for the CPU Unit. This aids high-speed processing in the system as a whole,
and reduces the load on the CPU Unit. In particular, by carrying out special
operations and transmitting back the results when an interrupt is received
from the CPU Unit, ASCII Units can act as co-processors for the CPU Unit.
ASCII Units each provide 200 Kbytes of user memory (BASIC program area
and variable area), enabling them to handle complicated applications.
A 32-bit MPU (C200H-ASC02 used an 8-bit processor) enables high-speed
processing.
The RS-422A/485 port enables long-range communications and 1:N commu-
nications.
In addition to previous commands (PC READ/WRITE, PC READ@/WRITE@,
and PC PUT/PC GET) it is also possible to execute PC QREAD/QWRITE trig-
gered by the ASCII Unit, as well as the PC EPUT/EGET commands, which
allow the ASCII Unit to read/write the memory shared between the ASCII Unit
and the CPU Unit. For the C200HX/HG/HE or CS1-series PCs, the CPU Unit
can immediately read/write the ASCII Unit using the IOWR/IORD instructions.
This means that the user can select the data exchange method to match the
application, including the read/write trigger, the Unit executing the read/write,
the read/write timing, the transmitted data size, and whether or not special
programming is required.
Section 1-1