VIPA System 300V - Page 96

Chapter 6 Deployment CPU 31x with TCP/IP Manual VIPA System 300V
6-6 HB130E - CPU - Rev. 11/50
The TCP transport service works stream orientated. This means that data
packages assembled by the user not necessarily have to receive the
partner in the same packaging. Packages may reach the partner and the
package borders are not recognized.
However, most applications require a message orientation.
This means that you need another protocol above TCP. This purpose is
defined in the protocol RFC1006. The protocol definition describes the
function of an ISO transport interface (ISO 8072) basing upon the transport
interface TCP (RFC793).
The basic protocol of RFC1006 is nearly identical to TP0 (Transport
Protocol, Class 0) in ISO 8073.
For RFC1006 is run as protocol for TCP, the decoding takes place in the
data section of the TCP package.
• The project engineering happens via VIPA WinNCS V 3.02 or higher.
• With RFC1006 only SEND and RECEIVE commands are permissible.
• If the CP should act as an active partner, a SEND order must be
projected, should it act as an passive partner you have to project a
RECEIVE order.
• For every SEND order, the CP automatically creates a RECEIVE order
and vice versa. The assignment of order numbers for the automatically
created orders is following this rules:
- SEND commands may only have odd order numbers. The automa-
tically generated RECEIVE order gets the next higher even order
number. (Example: SEND, ANR:5 → RECEIVE, ANR:6)
- RECEIVE commands may only have even order numbers. The auto-
matically created SEND order gets the next lower odd
order number. (Example: RECEIVE, ANR:2 → SEND, ANR:1)
• Automatically created orders are not monitored in WinNCS.
• For the addressing TSAPs are used instead of ports besides of the IP
address.
• The TSAP definition differentiates between small letters and capitals.
• The maximum length of TSAPs is 8 signs. The length has to be preset
in WinNCS.
• Independently from the used protocol the standard SEND and RECEIVE
commands of the PLC are necessary for data transfer.
RFC1006
Properties