The RMOS3-TCP/IP V3.0 software package contains a completely newly adapted TCP/IP protocol stack (TCPIP.DRV V3.0) with a data transmission time 30% less than that of RMOS3-TCP/IP V2.3.
RMOS3-TCP/IP V3.0 provides new communication services for the communication with higher-level server applications:
DHCP client features
The dynamic host configuration protocol (DHCP) allows the automatic configuration of IP addresses and subnetwork masks in a network. With the aid of a DHCP server, it is possible to integrated a computer (client) into an existing network without having to configure it manually. The complexity of administering the address configurations is reduced by the central administration of the IP addresses by means of a network server. Only the automatic reference of the IP address has to be set on the client. When starting the computer on the network, the client can obtain the IP address, the network mask, the gateway, the DNS server, etc. from the DHCP server.
Advantage:
This avoids collisions with manually set IP addresses that have accidentally been duplicated in a network, thus saving the consequential time-consuming troubleshooting.
DNS client features
The Domain Name System (DNS) is a distributed database for the central administration of the name space on the Internet. It compiles IP addresses into names (domains) or names into IP addresses, so that the computers and services can be addressed by means of user-friendly names.
Advantage:
When an IP address is dynamically assigned by means of DHCP, a specific PC can be addressed using a memorable, machine-level working name, thereby simplifying remote maintenance via the Web server.
NTP client features
The Network Time Protocol (NTP) is used for synchronizing the time between different computers in the network. The network time is queried by an NTP server, which ideally is synchronized using atomic clocks. A coordinated universal time (UTC) is then transmitted.
Advantages of automatic synchronization by means of NTP:
Automatic setting of the computer clock - even if there are several computers in a network. By avoiding the use of CMOS batteries, completely maintenance-free SIMATIC IPC solutions can be implemented, e.g. with the IPC427C.
SMTP client features
The SMTP protocol is used for sending e-mails to an SMTP server. The protocol is used predominantly for feeding and forwarding e-mails.
Advantage:
By means of a prepared function call, the machine can send the service engineer an e-mail without delay to notify him of any pending events.
Web server features
The version of the Web Server already available under RMOS3 has been updated for use with RMOS3-TCP/IP V3.0. The Web server (V1.1) permits the display of HTML pages, uploading/downloading of files and access to the process data of user applications under RMOS3.
Suitable library functions for exchanging data over the web server with RMOS3 applications are available to support this access.
Advantages:
With the aid of the web server, the user obtains
- central access to distributed/remote automation solutions based on SIMATIC IPC with RMOS3
- the visualization of process data
- the operation of headless systems (e.g. for commissioning and maintenance purposes)
For the remote maintenance of the SIMATIC IPC, the customer is given a Web server with HTML pages that can be adapted on an application-specific basis, into which the access to process tags can also be integrated.
Application programming features
For the application programming, plug-ins are again available for the Eclipse development environment (RMOS3-GNU V2.1 or higher):
- Online help:
Integration of the socket function calls into the online help of the Eclipse-IDE for high-speed access to the function description. - Code-completion:
The extended code completion is also available for the socket functions and supports the developer when creating the source codes by completing the socket calls that are entered. - Simulation:
The simulation of socket calls maps RMOS socket calls to Windows socket calls and thus facilitates a rough pre-testing of the RMOS3 application while it is still on the development system.
Prepared sample applications for RMOS3-GNU V2.1 or higher support the programmer when implementing the communication interface via the TCP protocol in blocking or non-blocking mode. For checking the node accessibility via the Ethernet, a PING-example is offered and can simply be integrated into the application.
An application example is used for explaining the interface of the FTP function block library in order to implement an FTP client under RMOS3. Further examples describe the dispatch of e-mails via SMTP and the clock synchronization by means of NTP.
Characteristics of TCP diagnostics
The following new supplementary programs are offered for the diagnosis of the TCP/IP stack:
- IPCONF for output of the configuration of the Ethernet controller (IP address, subnetwork mask and standard gateway) integrated in the TCP/IP stack. This permits a quick overview of the current Ethernet configuration in the system.
- ARP for configuration of the address resolution protocol (ARP) table of the TCP/IP stacks : Display of all communication partners that have already communicated with the local system. This enables, for example, duplicated IP addresses to be detected.
Further TCP utilities
TCP utilities such as FTP, FTPD, TELNET and TELNETD permit the exchange of files and the remote maintenance of the RMOS3 system via the LAN interface. Additional programs ensure accessibility via gateways/routers (e.g. the ROUTECFG program) and are used for the quick testing of the connection (PING).