DeviceNet构建于CAN总线的根底之上，运用CAN总线11位标识区，只运用标准帧。11位标识区中，5位用于表明报文类型(32种报文)，别的6位表明总线地址(64个地址)。
DeviceNet是一个简略的网络化解决方案，降低了本钱及安装设备和配线的时刻，并供给杰出的交换性，使得多家供货商的产品能够像组件相同能够交换。DeviceNet是一个敞开的网络标准。其标准和协议都是敞开的。供货商不用购买硬件，软件，或答应权限，就能够把设备接入一个DeviceNet体系。其标准文本能够从Open DeviceNet Vendor Association Inc.( ODVA)取得。
DeviceNet在达到很多杂乱设备之间的互操作性的一起，也答应简略设备之间的交换性。DeviceNet通讯衔接根据播送的通讯协议，即CAN协议。1996年，CAN芯片的出货量超越10million片。首要的一些CAN芯片的供货商有Intel, Motorola, Phillips and Hitachi.
DeviceNet的呈现有两个意图：
传送与现场级设备相关的操控信息.
传送其它与体系操控直接相关的信息，比方装备信息(Configuration).
DeviceNet的特色
下表列出了DeviceNet首要的物理前言层特性:
| 总线类型 | CSMA/BA, master-to-slave, explicit and solicited messaging. Unsolicited messaging, multiple masters, and peer-to-peer was introduced in early 1996 by the Systems SIG group of the ODVA for approval, conformance review and implementation in 1996 and 1997. |
| 节点总数 | 64 |
| 总线拓扑 | 带分支线的线性网络 |
| 通讯间隔 | 500 meters full trunk line, 6 meter branches @ 125 kbps 250 meters full trunk line, 6 meter branches @ 250 kbps 100 meters full trunk line, 6 meter branches @ 500 kbps 156 meters accumulative distance of the branches @ 125 kbps 78 meters accumulative distance of the branches @ 250 kbps 39 meters accumulative distance of the branches @ 500 kbps |
| 传输前言 | Full trunk line – 2 wire twisted shielded cable with 2 wire bus power cable and drain wire.Thin trunk line – same as full above but with lesser wire size which is more economical and easier to install. |
| 传输信号 | Square wave digital with NRZ (Non Return to Zero) encoding |
| 输入点数 | 64 bits (allocated in bytes) standard in polling mode, larger fragmented messages are supported. |
| 输出点数 | 64 bits (allocated in bytes) standard in polling mode 24 bits in explicit messaging. Fragmented messages are also supported. |
| 通讯速率 | 125 kbps, 250 kbps, 500 kbps |
| 总线电源 | 8 Amp full trunk line, 4 Amp thin line |
| 重复地址侦测 | Yes, nodes announce address on start-up and all listen. If a duplicate address is heard, the duplicate node will not advance to run mode. |
| 从站检测 | Yes, a list is programmed in the interface and checked |
| 过错侦测 | Yes, CRC |
| 过错纠正 | Yes, nodes that detect errors signal the sender to repeat. |
| 地址设定 | Off line via hand held programmer or with a dedicated interface and host.本文来自织梦 On line via the interface master using a reserved newcomer default address that is changed to an application address. Dip/rotary switches are optional. |
| 节点参数编程 | Can be very extensive to include drive/rotational and instrument parameters |
| 前史 | The early days of DeviceNet were essentially Allen-Bradley. In 1992, Allen-Bradley started to share information and invite not only strategic partners, but direct competitors to become DeviceNet members. DeviceNet was released at the ICEE show in Chicago, March 1994. Then, a year later,本文来自织梦 Allen-Bradley turned DeviceNet over to ODVA, Open DeviceNet Vendors Association. |
根据DeviceNet的网络架构
