Description
In addition to its PC/AT functions, the VMIVME-7740-850 has the following VMEbus features:
• Single-slot, 6U height VMEbus board
• Complete six-line Address Modifier (AM-Code) programmability
• VME data interface with separate hardware byte/word swapping for master and slave accesses
• Support for VME64 multiplexed MBLT 64-bit VMEbus block transfers
• User-configured interrupter • User-configured interrupt handler
• System Controller mode with programmable VMEbus arbiter (PRI, SGL, and RRS modes are supported)
• VMEbus BERR bus error timer (software programmable)
• Slave access from the VMEbus to local RAM and mailbox registers
• Full-featured programmable VMEbus requester (ROR, RWD, and BCAP modes are supported)
• System Controller autodetection
• Complete VMEbus master access through five separate Protected-mode memory windows Figure 1-2 illustrates the VMIVME-7740-850 functions in a typical VMEbus system.
The VMIVME-7740-850 is a versatile single-board solution for VMEbus control with familiar PC/AT operation. The VMIVME-7740-850 VMEbus interface is provided by the PCI-to-VMEbus bridge built around the Tundra Semiconductor Corporation Universe II VMEbus interface chip. The Universe II provides a reliable high-performance 64-bit VMEbus-to-PCI interface in one design. The functions and programming of the Universe-based VMEbus interface are addressed in detail in a separate associated manual titled: VMIVME-7740-850 Tundra Universe II Based VMEbus Interface Product Manual (500-657740-001).
VMIC’s VMIVME-7740-850 is built around three fundamental hardware configurations. These involve processor performance, the Flash Disk, and SDRAM memory size. These options are subject to change based on emerging technologies and availability of vendor configurations. The options and current details available with the VMIVME-7740-850 are defined in the device specification sheet available from your VMIC representative.
SCSI is a bus developed by IBM. The maximum transmission distance is 25 meters, usually within 3 meters. If it is SCSI I, the transmission speed is 5 M bytes/S. Each bus can connect 8 devices. If it is a SCSI II basic model, the transmission speed is 10 M bytes/S. Ultra SCSI is 20M bytes, and each bus can connect 16 devices. RS232 connection, data transmission speed of 300/S data, SCSI I connection, 1000/S data. The dedicated interface of DCS and the host connection of the operator station mostly use the SCSI I bus. Use the dedicated interface of DCS and the operator station host as nodes on the SCSI I. In addition, in theory, tape drives or external hard drives are used as backup means for DCS system software. For safety and reliability, the operator’s hard drive, tape drive, external hard drive, and optical drive are used as nodes on the SCSI. This backup method has a longer retention time than floppy disk backup.
Floppy disks are prone to damage after being used several times. The dedicated interface of DCS is usually composed of several cards. Among the several cards, the other cards are necessary to ensure the normal operation of these two cards, such as power cards. Two of them are the main cards, and one card is connected to a dedicated network, while the other card is connected to the operator station host. The data is exchanged between these two cards. The speed of data transmission to the operator station is mainly determined by the speed of data exchange between these two cards. For example, the ICI interface of INFI90 uses 8 parallel connections, with a speed of around 512Kbyte/S. Therefore, no matter how high the speed of SCSI is, it is of no use. But it is much faster than RS232.