Emerson manual Rosemount 848L, Reference Manual, 00809-0100-4696,Rev AA September

Rosemount 848L

Reference Manual

00809-0100-4696, Rev AA September 2004

EQ - Channels 17-32 are set by the result of an equation specified by up to 80 characters and stored in parameter EQx, where x is the equation number. The equation results are available as a discrete value and status in parameter EQx_VALUE. They may be referenced by the EQ (u) function. The range of ‘u’ is 1 to 16. These are intended to be intermediate values that are used because the value is used in other equations or because the equation text was too long. A configured DI block may use an equation channel (range 17 to 36) in order to make the result available to other devices.

OUT – The value will be the same as the requested output.

Additional Channels

The ten channels that are used for connecting multiple in or out function blocks can not be referred to by equation functions. Each has a status that is Bad if any Input status is Bad. Channels 37 to 41 pack the values into one byte so that a DI or DO function block can read or write them. Any block linked to a DI block with packed data must be capable of handling the packed boolean values. Channels 42 to 46 may be used with standard MDI or MDO blocks.

Channel	Type	FB
37	All IN	DI
38	All DO	DO
39	First 8 EQ	DI
40	Last 8 EQ	DI
41	All OUT	DO
42	All IN	MDI
43	All DO	MDO
44	First 8 EQ	MDI
45	Last 8 EQ	MDI
46	All Out	MDO

Reading a channel value will reset all of the channel latches that are configured. Channels 38 and 43 do not have latches. If a DI and a MDI are both used they will interfere with the latches, but the user is expected to use one or the other, never both.

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