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Df1 programming example (cont’d) – Rockwell Automation 5370 CVIM Communications Manual User Manual

Page 132

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Chapter 5

Using the RS–232 Ports

5–62

case DLE:

if ( message_started )

{

if ( ++length > MAX_BUFFER )

{

_bios_serialcom(_COM_SEND,portnum,DLE);

_bios_serialcom(_COM_SEND,portnum,NAK);

last_response = 0;

message_started = 0;

err = 0;

length = 0;

df1_bcc = 0;

msg = msg_start_ptr;

}

else

{

*msg++ = ( ch & 0xFF );

df1_bcc += ( ch & 0xFF );

}

}

break;

case ENQ:

if ( last_response )

{

_bios_serialcom(_COM_SEND,portnum,DLE);

_bios_serialcom(_COM_SEND,portnum,NAK);

}

else

{

_bios_serialcom(_COM_SEND,portnum,DLE);

_bios_serialcom(_COM_SEND,portnum,NAK);

}

break;

default:

break;

}

}

else if ( message_started )

{

if ( ++length > MAX_BUFFER )

{

_bios_serialcom(_COM_SEND,portnum,DLE);

_bios_serialcom(_COM_SEND,portnum,NAK);

last_response = 0;

message_started = 0;

err = 0;

DF1 Programming
Example (cont’d)