4 write lock (write-protect) function, Write lock (write-protect) function -5 – Yokogawa FVX110 User Manual

Page 68

<9. In-Process Operation>

9-5

IM 01S01C01-01EN

9.4 Write lock (Write-protect)

function

The FVX110 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 FVX110 is provided with

a write lock switch (switch 2 in Figure 9.5). Setting

switch 2 to On activates the write lock function, to

prevent changes to block parameters of WRITE_

LOCK_LEVEL (index 1064). Table 9.4 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 LCD

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).

Table 9.4

Relationship between WRITE_LOCK_

LEVEL and block targeted by write lock

WRITE_LOCK_

LEVEL

Block targeted by Write lock

All parameters for the LCD

transducer block and FEATURE_

SEL and WRITE_LOCK_

LEVEL parameter settings for

FEATURE_SEL

All parameters for the LCD

transducer block and resource

block

(Factory default)

All function block parameters

in addition to WRITE_LOCK_

LEVEL “1”

MIB and VCR in addition to

WRITE_LOCK_LEVEL “2”

When the write lock switch is disabled, set 2

(enabled) for WRITE_LOCK (index 1034) of the

resource block to enable the write lock function. To

enable the write lock function using the WRITE_

LOCK setting, FEATURE_SEL (index 1018) of

the resource block must be returned to its factory

default. (In the factory default setting, “Hard W

Lock” (bit 4) is “0” (Off and “Soft W Lock” (bit 3) is

“1” (On).

Table 9.5

FEATURE_SEL, write lock switch and

WRITE_LOCK parameter relationship

FEATURE_SEL

Write

lock

switch

WRITE_LOCK

Hard

Lock

(bit4)

Soft

Lock

(bit3)

(OFF)

Disabled

Unavailable

(“1” (Write lock

disabled)

1 (ON)

1 (Write lock disabled)

(Factory default)
2 (Write lock enabled)

1 (ON) 0

(OFF)

Enabled

Unavailable

(depends on write lock

switch)

* When “Hard W Lock” and “Soft W Lock” are both 1 (On), the

“Hard W Lock” setting takes precedence and “Soft W Lock” is

automatically set to 0 (Off).

"OFF" during operation

WRITE LOCK

Amplifier Assembly

F0905.ai

Figure 9.5

WRITE_LOCK Switch