PS (channel number, divisor);

Reference Manual

00809-0100-4696, Rev AA September 2004

Rosemount 848L

Table D-1. Supported Functions

 

Required number

Maximum number

 

Maximum

Function Name

of parameters

of parameters

Function Description

Instances

 

 

 

 

 

PS

2

2

PS (channel number, divisor);

10

 

 

 

This function is a frequency prescaler. This function's

 

 

 

 

value will be true for 1 execution cycle each time the

 

 

 

 

requested device input has had 'divisor' pulses. This is

 

 

 

 

ideal for a scaling fast pulse inputs to a rate suitable for

 

 

 

 

the logic execution cycle.

 

 

 

 

 

 

RISE

1

1

RISE (a);

10

 

 

 

This function is a rising edge trigger. When 'a'

 

 

 

 

transitions from false to true, this function's result is

 

 

 

 

true, otherwise it is false.

 

RS

2

2

RS (set, reset);

10

 

 

 

This function is a reset dominant latch. When 'reset' is

 

 

 

 

true, this function will reset its' state to false regardless

 

 

 

 

of the value of 'set'. When 'reset' is false, the function's

 

 

 

 

state will have a false value until 'set' has had at least 1

 

 

 

 

true reading, after which the state will remain true. The

 

 

 

 

result of this function is the function's state.

 

 

 

 

 

 

SHL

3

4

SHL (a, clock, reset, bit);

10

 

 

 

This function is an 8 bit left shift register. When 'clock'

 

 

 

 

transitions from false to true, the value of 'a' is shifted

 

 

 

 

into the least significant bit of this function's register.

 

 

 

 

The remaining bits are shifted left by 1 bit position.

 

 

 

 

When 'reset' is true, all 8 bits in this function's register

 

 

 

 

will be cleared to zero. 'reset' is an optional parameter

 

 

 

 

and will always be considered false if it is not present.

 

 

 

 

The result of this function is the value of bit number 'bit'

 

 

 

 

in the register.

 

SHR

3

4

SHR (a, clock, reset, bit);

10

 

 

 

This function is an 8 bit right shift register. When 'clock'

 

 

 

 

transitions from false to true, the value of 'a' is shifted

 

 

 

 

into the most significant bit of this function's register.

 

 

 

 

The remaining bits are shifted right by 1 bit position.

 

 

 

 

When 'reset' is true, all 8 bits in this function's register

 

 

 

 

will be cleared to zero. 'reset' is an optional parameter

 

 

 

 

and will always be considered false if it is not present.

 

 

 

 

The result of this function is the value of bit number 'bit'

 

 

 

 

in the register.

 

 

 

 

 

 

SR

2

2

SR (set, reset);

10

 

 

 

This function is a set dominant latch. When 'set' is true,

 

 

 

 

this function will set its' state to true regardless of the

 

 

 

 

value of 'reset'. When 'reset' is false, the function's state

 

 

 

 

will have a false value until 'set' has had at least 1 true

 

 

 

 

reading, after which the state will remain true. When

 

 

 

 

reset is true, the function's state will be set to the value

 

 

 

 

of 'set'. The result of this function is the function's state.

 

TOF

2

2

TOF (a, time);

10

 

 

 

This function is an off delay. When 'a' is true, this

 

function will set its' output to true. When 'a' transitions to false, the function's output will remain true for 'time' * 100 milliseconds before going false.

D-3

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Emerson manual Rosemount 848L, Reference Manual, PS channel number, divisor