Multistate bit format input

Number of Input Bits

Enter a value from 1-8 that defines the type of the multistate point.

For 8-bit devices, input bit 1 (Input #1) is the low-order bit, and input bit 8 (Input #8) is the high-order bit.

Use the following examples to determine how to configure this field:

• 0. For digital output devices that do not return "command success" messages. With this setting, no Input# needs to be configured.

• 1. For two-state devices. With this setting, Bit #1 and Input #1 must be configured.

• 2. For four-state devices. With this setting, Bit #1 and Bit #2 and Input #1 and Input #2 must be configured.

• 3. For eight-state devices. With this setting, Bit #1, Bit #2, and Bit #3 and Input #1, Input #2 and Input #3 must be configured.

  ...

• 8. For 256-state devices. With this setting, Bit #1-8 and Input #1-8 must be configured.

  The Input tab in the multistate Row Edit dialog box has similar configuration areas for input values. The input sections configure the way multistate points reads the input.

Bit

These numbers list the sequential number of rows.

Bit in RTU Status

Select if this record is monitoring a remote-specific condition. If this is selected, only the Bit Number field needs to be configured.

In some protocols, such as TANO, the remote status word (RSW) is an 8-bit status word that is returned to the host. Each bit in this word represents a remote-specific condition, such as:

• AC power-fail

• bulk power fail in one or more expansion baskets

• unit powered up

• command disabled

• uninitialized

Coordinates

Enter the coordinates where the data is mapped within the remote. This mapping depends on the protocol used.

Some protocols use registers to allocate data in remote memory, others use a definition of the point or file number for access. Representative data mappings and point configuration are described for various protocols in RealTime. Refer to your specific remote or protocol documentation for a definition of the data mappings and to determine the remote’s input/output data location in memory.

Bit Number

Enter the device’s status bit number.

A single word of RealTime data can encode messages from a number of status/multistate devices. The Bit Number field points to the device’s status bit number within that word.

Normally Open

Select if your remote does not return a value of 1 to indicate open.

The system expects a value of 1 to indicate open. When Normally Open is selected, the bits from the remote are inverted (for example., 0 is changed to 1 and 1 is changed to 0). If cleared, the bits that are returned from the remote remain unprocessed.