1785-V30B

The Allen-Bradley 1785-V30B is a PLC-5 Programmable Logic Controller. VMEbus is a computer bus standard, developed for the Motorola 68000 line of CPUs, but later used for many applications. The 1785-V30B processor belongs to series of enhanced PLC-5 processors. The 1785-V30B processors share all the features and specification with enhanced PLC-5 processors PLC-5/30. In addition to those features, 1785-V30B is also compliant with the C.1 VMEbus specification. That means that 1785-V30B can be connected to VMEbus system via VMEbus chassis and that 1785-V30B has an integrated VMEbus system communication interface designed for use with other VMEbus CPU modules. Additionally, the same interface provides communication with VMEbus I/O modules. 1785-V30B has is not equipped with an EEPROM memory module The 1785-V30B has 32,000 words of user memory. It can also support a total of 896 inputs/outputs in any combination. These inputs/outputs can be arranged in complementary 896 in or 896 out combinations. Additionally, the 1758-V30B can support up to 896 analog signals.

The program scan time for 1785-V30B varies from 2 milliseconds per 1,000 words, which is typical, or 0.5 milliseconds per 1,000 words, which is used for bit logic. The I/O scan time is 0.5 milliseconds for extended local I/O, and 10 milliseconds per rack for a transmission rate of 57.6 kbps, 7 milliseconds per rack for 115.2 kbps transmission rate and 3 milliseconds per rack for 230 kbps. The following transmission rates are available: 57.6 kilobytes per second, 115.2 kilobytes per second and 230 kilobytes per second.  The 1785-V30B has two ports that can be used as DH+ or remote I/O ports. None of the ports are compatible with extended local I/O ports. The maximum number of I/O racks that can be connected to 1785-V30B is 7 and 28 I/O chassis can be connected remotely. This processor has one RS-233 port.

On the front panel of the 1785-V30B, there are a few communication channel connections. Channel 0 is a 25-pin D-shell connector with an optically coupled serial port which supports EIA RS-232C and ASCII or DF1 protocol. Channel 1A and Channel 1B are 3 pin connector ports which are used as user configurable ports that support scanner, adapter, and Data Highway Plus (DH+) communication modes. The programming terminal has an 8-pin mini-DIN connector and is used for programming the processor. The 1785-V30B is programmed in the same manner as the enhanced PLC-5/30 processors. In addition to the shared features, the 1785-V30B has some additional features that are not present in enhanced PLC-5/30 processors. For example, the 1785-V30B supports VME status files, which are file ladder programs that grant the user the ability to control and monitor specific VMEbus data and information. Additionally, the 1785-V30B has extended ladder MSG instructions that allow ladder programs to perform VMEbus data transfers and generate VMEbus interruptions.  The 1785-V30B occupies 2 slots in the 6U full height VMEbus chassis. You can program and monitor the 1786-V30B using DH+ link, using Serial communication - on channel 0 - and VMEbus backplane connection.