Using the znd and znm tokens – Tyco F3200 User Manual

Page 134

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F3200 Installation & Programming Manual

Document No: LT0122

Programming System Configuration

Page 7-32

5 July 2001

Issue 2.7

EXAMPLE EQUATIONS (CONTINUED)

(iii)

To reset a zone after it has been in alarm for 30 seconds.

T1[S30:0]=Z1A

ZR1:1=T1

After zone 1 alarm (Z1A) has been true for 30 seconds, timer T1 will become true

and a reset command will be issued to zone 1. This will immediately cause Z1A to

become false, resulting in timer T1 becoming false and removing the reset command

initiation. If the zone subsequently goes back into alarm, then after a further 30

seconds it will be reset again.

Note: If the zone is isolated then it will NOT be reset 30 seconds after being in alarm

due to the fact that the Z1A token is false for an isolated zone.

7.4.10

USING THE ZND AND ZNM TOKENS

Some applications require the use of a switch, where the state of the switch can be

accessed in output logic. One of the zone output logic tokens listed in Section 7.4.3.1 would

normally be used to access the state of the switch - ZnA, ZnF, ZnN, ZnD, ZnM, ZnI or ZnR.

For example if a short circuit state is produced when the switch closes then band B1 could

be programmed as instant alarm and the ZnM token will become true when the state of the

circuit is short circuit/B1.

The ZnD and ZnM tokens have a faster "response" time (80-240 millisecs) than ZnA or ZnF.

As described in section 7.2.4 "Time Delays", for V2.XX software a type 4 circuit with an into

alarm delay of zero has an actual delay of 200 to 800 millisecs (typically 400 millisecs) which

means that the ZnA and ZnF tokens become true within 200 to 800 millisecs. Otherwise the

time delay for the ZnA and ZnF tokens is 2.0 to 2.3 seconds. The ZnD and ZnM tokens are

not affected by whether the zone is isolated or not (unlike ZnA and ZnF) but the ZnI token

can be used in an equation to qualify the ZnD and ZnM tokens if necessary.

Which zone token to use and which circuit delay type to program depends on the response

time required for the switch.

There are some other special considerations to note when using the ZnD and ZnM tokens.

In particular, during system or auto test or at the termination of a zone alarm test the circuit

input may be briefly in the band B3 state long enough for ZnD or ZnM token to become

briefly true. During system/auto test if band B3 is programmed as "detector operated" or as

"instant alarm" then the ZnD or ZnM tokens will be true for the 1 to 2 seconds that the circuit

is in band B3 during the test.

A "status only zone" (refer Section 7.3.2 configuring zones), does not get tested during

system or auto test and hence will not have the problem of the circuit going into band B3

during system test.

During zone alarm test the state of the circuit will appear to be in band B2 (unlike

system/auto test). However, if the zone test is terminated by pressing the ACK key without

resetting the zone, then the circuit will appear to be in band B3 for a short time (approx 200

millisecs) - long enough to cause the ZnD or ZnM tokens to return true for a short time,

depending on the programming of band B3. When a zone is reset the ZnD and ZnM tokens

are prevented from changing during the 7 second reset operation as described in section

7.4.3.1.

Therefore for a "status only zone" it is recommended that band B3 be programmed as

normal rather than instant alarm.

Note that for V2.XX software the default mapping for band B3 is "instant alarm" which is the

state that causes the ZnM token to be true.

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