3 simulation function, 4 write lock (write-protect) function, Simulation function -4 – Yokogawa EJX930A User Manual

Page 56: Write lock (write-protect) function -4

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<7. In-Process Operation>

7-4

IM 01C25T02-01E

7.3 Simulation Function

The simulation function simulates the input of a

function block and lets it operate as if the data was

received from the transducer block. It is possible to

conduct testing for the downstream function blocks

or alarm processes.
A SIMULATE_ENABLE switch is mounted in

the transmitter amplifier. This is to prevent the

accidental operation of this function. When this is

switched on, simulation is enabled. (See Figure

7.2.) To initiate the same action from a remote

terminal, if REMOTE LOOP TEST SWITCH is

written to the SIM_ENABLE_MSG parameter

(index 1044) of the resource block, the resulting

action is the same as is taken when the above

switch is on. Note that this parameter value is

lost when the power is turned OFF. In simulation

enabled status, an alarm is generated from the

resource block, and other device alarms will be

masked; for this reason the simulation must be

disabled immediately after using this function.
The SIMULATE parameter of AI block consists of

the elements listed in Table 7.3 below.

Table 7.3

SIMULATE Parameter

Subindex

Parameters

Description

1

Simulate Status

Sets the data status to

be simulated.

2

Simulate Value

Sets the value of the

data to be simulated.

3

Transducer Status Displays the data status

from the transducer

block. It cannot be

changed.

4

Transducer Value Displays the data value

from the transducer

block.It cannot be

changed.

5

Simulate

En/Disable

Controls the simulation

function of this block.

1: Simulation disabled

(standard)

2: Simulation started

When Simulate En/Disable in Table 7.3 above is

set to 2, the applicable function block uses the

simulation value set in this parameter instead of

the data from the transducer block. This setting can

be used for propagation of the status to the trailing

blocks, generation of a process alarm, and as an

operation test for trailing blocks.

F0702.ai

Amplifier Assembly

1

2

O

N

"OFF" during operation

Write lock switch

SIMULATE_ENABLE

Figure 7.2

SIMULATE_ENABLE Switch Position

7.4 Write lock (Write-protect)

function

The transmitter is provided with a write lock (write-

protect) function to restrict write operations to

blocks and prevent inadvertent writing of parameter

data. To enable this function, use the write lock

switch (Hard W Lock) or the WRITE_LOCK (index

1034) (Soft W Lock).

The CPU assembly of the transmitter is provided

with a write lock switch (switch 2 in Figure 7.3).

Setting switch 2 to On activates the write lock

function, to prevent changes to block parameters

of WRITE_LOCK_LEVEL (index 1064). Table 7.4

shows how WRITE_LOCK_LEVEL relates to the

block targeted by write lock. In the factory default

setting, WRITE_LOCK_LEVEL is “2” (preventing

writing to the transducer block, resource block and

function block). To enable the switch lock function,

set "Hard W Lock” (bit 4) of FEATURE_SEL (index

1018) to “1” (On). (The factory default for “Hard W

Lock” (bit 4) is “0” (Off).

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