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发表于：2002-10-15 09:17:00

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We are comparing the chip cost for several different device-level networks. Which DeviceNet chips would be comparable to the following Profibus chips? Profibus DP Master Chip, Model #ASPC2 Profibus DP Remote I/O Chip, Model #LSPM2 Profibus DP SPC3 Intelligent Device Chip, Model #SPC3 Answered by Nick Jones, System Architecture SIG, e-mail: A119) DeviceNet devices use a CAN chip for the data link layer functions, but the DeviceNet protocol is implemented in a separate microprocessor with additional software. Single-chip microcontrollers with CAN (used in most DeviceNet slave devices) have the same footprint as the Profibus DP slave equivalent (SPC# Intelligent Device Chip) and could be considered comparable. More complex slave devices and masters/scanners use stand-alone CAN chips with a separate microprocessor. Here are my personal recommendations for suitable components for various applications. (The list is not complete and is based solely on my experience): Master Applications: require more extensive processing power, so I recommend a stand-alone CAN chip with separate CPU. Stand-alone CAN controller * Intel 82527 * Philips 82C200 (discontinued) * Philips XJA1000 (replaces 82C200) Microprocessor * 80186, 25-40 MHz minimum * 80386, (check interrupt latency before selecting this chip) Memory * 64K ROM, 64K RAM minimum (I recommend more if possible) Complex Device Applications or Remote/Block I/O: typically use fragmented messaging (messages larger than 8 bytes) and require more processing power and memory than a simple device. You could use the same components listed above for a scanner or one of the high-end microcontrollers with CAN. Microprocessor with CAN * Siemens C167CR * Philips XA-C3 Simple Devices: typically use un-fragmented messaging (8 bytes or less I/O) and have lower CPU and memory requirements. Use the lower cost microcontrollers with CAN. Microprocessor with CAN * Philips 82C592 (replaced by XA-C3) * Philips XA-C3 * Motorola 680HC705X4 * Motorola 680HC705X16 (mask ROM) * Motorola 680HC705X32 * Siemens C167CR * Siemens C515C8

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﻿问答系列（五） ﻿点击：1834 | 回复：0

问答系列（五）点击：1834 | 回复：0