User manual OMRON CJ1W-ETN21 04-2009

[. . . ] W420-E1-06 SYSMAC CS and CJ Series CS1W-ETN21 (100Base-TX) CJ1W-ETN21 (100Base-TX) Ethernet Units Construction of Networks OPERATION MANUAL CS1W-ETN21 (100Base-TX) CJ1W-ETN21 (100Base-TX) Ethernet Units Construction of Networks Operation Manual Revised April 2009 iv Notice: OMRON products are manufactured for use according to proper procedures by a qualified operator and only for the purposes described in this manual. The following conventions are used to indicate and classify precautions in this manual. Always heed the information provided with them. Failure to heed precautions can result in injury to people or damage to property. !DANGER !WARNING Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury. [. . . ] If using TCP is like making a telephone call, then UDP is more like delivering a memo by hand. Although the UDP protocol is fast, data communications are less reliable than with TCP. In particular, when sending large amounts of data involving significant routing, the user must program measures, such as retries, into applications in order to improve reliability. Node Node FINS/UDP Features Data transmission 1 Data transmission 2 Data transmission 3 Data is sent in one direction, with no confirmation of whether the data was received. Because there are few procedures involved, data can be sent at high speed but with less reliability than with TCP. The FINS/UDP method has the following features: · Because FINS/UDP is a connectionless protocol, there is no limit to the number of corrections. · FINS/UDP can be used for broadcasting. · When data is sent via an IP network with multiple layers (such as the Internet), communications reliability drops. FINS/UDP Frame Format The following diagram shows the structure of a UDP packet used for sending and receiving data on an Ethernet network. Ethernet Ver. 2 IP UDP FINS frame FCS UDP packet As the diagram shows, a nested structure is used with the FINS/UDP method, i. e. , Ethernet Ver. A UDP data section (FINS frame) that exceeds 1, 472 bytes is split into packets for transmission. The split UDP data is then joined automatically at the UDP/IP protocol layer. There is normally no need to pay attention at the application layer to this split, but it may not be possible to send 1, 472-byte UDP packets over an IP network with multiple layers. When using the FINS communications service in a system such as this, select the FINS/TCP method. 118 FINS/UDP Method UDP Port Numbers for FINS/UDP Section 6-2 The UDP port number is the number for UDP to identify the application layer (i. e. , the FINS communications service in this case). When communications are executed by UDP/IP, this port number must be allocated to the communications service. The default setting for the FINS/UDP local UDP port number (i. e. , the Ethernet Unit's UDP port number) is 9600. To set another number, make the setting for the FINS/UDP port using the Setup Tab in the Unit Setup. At the Ethernet Unit, a UDP/IP frame received with a FINS/UDP port number is recognized as a FINS frame. Procedure for Using FINS/UDP 1. Refer to SECTION 2 Startup Procedure in the Operation Manual Construction of Networks. With the CX-Programmer connected online, select the Ethernet Unit in the CX-Programmer's I/O Table Window. Then make the following settings in the Unit Setup Window. Setup Tab · Broadcast · FINS/UDP port (Default: 9600) · IP address table (for the IP address table method only) 3. Make the routing table settings and transfer them to each PLC. (See note. ) Set the routing tables with CX-Integrator, and transfer it to each PLC. [. . . ] P, changed "CX-Net" to "CX-Integrator", and changed "CX-Programmer" to "CX-One". Page xv: Removed manuals and added others and changed details for manuals W446 and W336. Page 30: Changed the reference for creating I/O tables. Page 40: Removed model number for the CX-Programmer and added information on relevant manuals. [. . . ]