Rockwell-automation 5370-UPK CVIM USER-PAK Option Manual de usuario descargar pdf (Pagina 44)

Chapter 6

Creating Custom Serial Port Messages

6–2

How many strings can be defined?

The CVIM module can store up to 340 strings, depending on how much of

the CVIM module’s memory is used for other purposes.

Can the custom serial port messages coexist with the standard RS–232

port communications with a host device?

The custom serial port messages may interfere with the transmission of the

response to a command from an RS–232 device. For this reason, a command

is available which allows you to disable and enable the transmission of

custom serial port messages (see Appendix C).

Do you need to set up any CVIM module parameters when using custom

serial port messages?

Yes, you need to select ASCII protocol, and select the appropriate baud rate

for the RS–232 port you are using.

You create a custom serial port message by defining a “string” for a given

serial port. It is the content and definition of the string that determine what

information will be sent through the serial port, and when it will be sent.

Using the string entry keyboard, you enter specific “elements” – literal text,

and/or codes of various types – which result in the transmission of one or

more corresponding “fields” comprising the serial port message.

Also, aside from defining the string content, you must specify the “event” for

each string – that is, the circumstances under which the string is transmitted.

You can also utilize a string repetition feature to transmit a single message

multiple times for the same event.

Example of a Serial Port Message String

This section provides an example of a serial port message string, for the

purpose of demonstrating string text, and the resulting message content.

Assume the gage 1 result for an inspection is 25.3, and the string text is

“Gage 1 Result =” g1

where the g1 in the string text is a “data code” which represents the results

from gage 1. The message transmitted would be these ASCII characters –

Gage_1_Result_= _ _ _25.300 (where _ indicates a space character)

For a listing of the entire ASCII character set, refer to Appendix B.

Creating Custom Serial

Port Messages

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Rockwell-automation 5370-UPK CVIM USER-PAK Option Manual de usuario Pagina 44