Characteristic Data Open User Communication Incl. E-Mail - Siemens CM 1542-1 Operating Instructions Manual

Properties and functions
1.3 Configuration limits and performance data
Note
Connection resources CPU dependent
Depending on the CPU type, different numbers of connection resources are available. The
number of connection resources is the decisive factor for the number of configurable
connections. This means that the values that can actually be achieved may be lower than
specified in this section "Properties and functions" describing the CM.
1.3.3

Characteristic data Open User Communication incl. e-mail

Open User Communication (OUC) provides access to communication over TCP, ISO-on-
TCP and UDP connections.
Characteristic
Number of connections
Maximum data length for program blocks
LAN interface max. data field length generat-
ed by the CM per protocol data unit(TPDU =
transport protocol data unit)
14
Explanation / values
Max. number of connections in total (configured and programmed:
•
(ISO-on-TCP + TCP + UDP + e-Mail) ≤ 64
of which:
– TCP connections: 0 ... 64
– ISO-on-TCP connections: 0 ... 64
– Total number of UDP connections (specified and free) that can be
configured: 0 ... 64
– Connection for e.mail: 0 ... 64;
only one e-mail can be processed at any one time
Notes:
Avoid overload at receiving end
• 1)
The flow control on TCP connections cannot control permanent over-
load of the recipient. You should therefore make sure that the pro-
cessing capabilities of a receiving CM are not permanently exceeded
by the sender (approximately 150 200 messages per second).
Program blocks allow the transfer of user data in the following lengths:
1. ISO-on-TCP, TCP: 1 - 64 kbytes
2. UDP: 1 - 1452 bytes
3. E-mail (job header + user data): 1 - 256 bytes
e-mail attachment: ≤ 64 kbytes
For sending
•
– ISO-on-TCP, TCP: 1452 bytes / TPDU
For receiving
•
– ISO-on-TCP: 512 bytes / TPDU
– TCP: 1452 bytes / TPDU
Operating Instructions, 07/2019, C79000-G8976-C355-04
1)
CM 1542-1