FC 61 - Blink

The blink function code generates a pulsating output signal. When <S1> and <S2> are logic 1, the output toggles between logic 1 and logic 0. The duration of either the logic 0 or logic 1 state is dependent on the cycle time of the block. The duration of either logic state is limited to be no less than 0.2 second. Output N equals <S1> until <S1> and <S2> equal one, then output N blinks. Refer to Table 61-9 for all possible output values.

 

Outputs:

Blk

Type

Description

N

R

Refer to Table 61 - 9

 

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

N

0

I

Note 1

Block address of first input

S2

N

0

I

Note 1

Block address of second input

 

NOTES:

1. Maximum values are: 9,998 for the BRC-100, IMMFP11/12 and 31,998 for the HAC

 

 

 

61.1  Applications

 

Figure 61-1 shows how to use function code 61 for alarm indication. The source receives the alarm signal and sends the signal to a blink block and a timer block. The timer block outputs a boolean signal. In this example, the timer is the timed out option. If the length of the input pulse is greater than or equal to the timing interval (S3 of function code 35), a logic 1 will be output for the length of the pulse once it has exceeded the timing interval. If the length of the pulse is shorter than the timing interval, a logic 0 will be the output. The output of the timer block is the <S1> input for a memory block. An external alarm

acknowledgment signal is the <S2> input to the memory block. The acknowledge signal is logic 0 if the alarm has not been acknowledged and logic 1 if it has.

 

If the point is in alarm, a logic 1 signal will be sent to both the blink and timer blocks. The duration of the logic 1 signal is longer than the timing interval, so the output of the timer block is a logic 1. If the alarm has not been acknowledged, then the S2 input to the memory block will be a logic 0. When <S1> equals logic 1 and <S2> equals logic 0, the output of the memory block is a logic 1. Thus, both inputs to the blink block are logic 1 and the output will toggle between logic 1 and logic 0. Once the alarm is acknowledged, the output of the memory block goes to logic 0, causing the output of the blink block to track the <S1> input. When the point comes out of alarm, both inputs to the blink block will be logic 0, and the output will be logic 0.

 

The OR (function code 39) forces the blink action to remain active and in alarm until the alarm is acknowledged whether or not the alarm signal is still present. If the signal is still in alarm when acknowledged, the value remains alarmed but the blinking action stops.