OPC90 Server
the PASSWORD tag. Note that OPC90 will automatically invalidate the
PASSWORD tag after 60 minutes transpires with no OPC client write activity to
the OPC90 BLK block.
7.3.5 Writing Bailey Controller Blocks
To write Bailey function blocks to a controller it must be in the configure mode of
operation. See the preceding section to understand how to change Bailey
controller modes of operation. There are five easy steps an OPC client must
follow to write a Bailey function block. First it writes the function code number of
e intended new block to the FC tag. Second it writes the new block number to
_BLOCK tag.
it requests the default specification settings for the
ode by set
of
ns is return
ion
S01_VA
ation
descriptors in the S01 through S63 tags. Completion of the read default request
en the D
ill
also return a text mess
r
if
ce
tep is to change the
ertinent to the new block about to be written. This is
ion code and the block write occurs. Completion of the write
is flagged wh
RITE tag is reset to FALSE. The MESSAGE tag
return a text m
r the
ailure if the
is
zero the request was successful, non-zero indicates an error occurred.
iley func
f
operation. See sectio
r
modes of operation. There are three easy steps an OPC client must follow to
ti
modified. See section 7
to change the approp
ifications from their current values to the values
his is accomplished by writing to the S01_VALUE through
ALUE throu
_VALUE tags appropriate for the block function
th
the ADDR
Third
function c
specificatio
ting the DEFAULT tag to TRUE. The number
ed in the SPEC_COUNT tag, the default specificat
values in the
LUE through S63_VALUE tags and the specific
is signaled wh
EFAULT tag is reset to FALSE. The MESSAGE tag w
age indicating completion of the read default operation o
it cannot be completed. When the ACKNAK tag
the reason for failure
the request was suc
is zero
ssful, non-zero indicates an error occurred. The fourth
appropriate specifications from their default values to
s
values that are p
accomplished by writing to the S01_VALUE through S63_VALUE tags. Note that
these tags are always written as floating point values. OPC90 will automatically
take care of translating the values to the appropriate types required by the Bailey
function block. The fifth and last step is to request OPC90 to actually write the
block to the Bailey controller. This is accomplished when the WRITE tag is set
TRUE. The value of the S01_VALUE through S63_VALUE tags appropriate for
the block function code are translated to the correct data types required for the
ailey funct
B
operation
en the W
will also
essage indicating completion of the write operation o
reason for f
write cannot be completed. When the ACKNAK tag
7.3.6 Modifying Bailey Controller Blocks
To modify a Ba
tion block, the controller must be in the configure mode o
n 7.3.4 to understand how to change Bailey controlle
modify a Bailey func on block. First it must read the function block to be
.3.1 to understand how to read a block. The second step
riate spec
is
to be modified. T
S63_VALUE tags. Note that these tags are always written as floating point
values. OPC90 will automatically take care of translating the values to the
appropriate types required by the Bailey function block. The third and last step is
request the block modification by setting the WRITE tag TRUE. The value of
to
the S01_V
gh S63
The RoviSys Company
Version 7.0
Page 47