Emerson PaCSystems VersaMax Series, Руководство пользователя

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User Manual Chapter 10
GFK-1503F Jan 2020
Instruction Set Reference 157
Example
In the example, coil E3 is ON when reference E1 is ON and reference E2 is OFF.
Figure 143
Negated Coil
A negated coil sets a discrete reference ON when it does not receive power flow. It is not
retentive, so it cannot be used with system status references (%SA, %SB, %SC, or %G).
Example
In the example, coil E3 is ON when reference E1 is OFF.
Figure 144
Retentive Coil
Like a normally open coil, the retentive coil sets a discrete reference ON while it receives
power flow. The state of the retentive coil is retained across power failure. Therefore, it
cannot be used with references from strictly non-retentive memory (%T).
Negated Retentive Coil
The negated retentive coil sets a discrete reference ON when it does not receive power flow.
The state of the negated retentive coil is retained across power failure. Therefore, it cannot
be used with references from strictly non-retentive memory (%T).
Positive Transition Coil
If the reference associated with a positive transition coil was OFF , when the coil receives
power flow it is set to ON until the next time the coil is executed. (If the rung containing the
coil is skipped on subsequent sweeps, it will remain ON.) This coil can be used as a one-shot.
Do not write from external devices (e.g., PCM, programmer, ADS, etc.) to references used
on positive transition coils since it will destroy the one-shot nature of these coils.
Transitional coils can be used with references from either retentive or non-retentive
memory (%Q, %M, %T, %G, %SA, %SB, or %SC).