OPC90 Server
3.) When the Device block “Set bad quality of max exception timeou
QUALITY tag of this block will be set bad if writes to the block input(s) do not occur within the
t” property is enabled, the
quest to go to a given state is written to the
tag value to the GOOD_STATE tag value
the MSDD block contains three
tputs as co als ice typically having more
tes. exam have a stopped,
an state i ur device states.
e fault condition and states one through three. Setup of the
def e ou o f
ree
be res te one set
ate 3 migh l three outputs are set. For compatibility with the Bailey
ion report this b t value
the disc . or
determining the actual device state but is
Bailey implementation. Instead, the Baile _STATE and
TE tag eterm ual device state and its new requested
state. The client writes the actual devic g as a
– 3. st new the
_STATE tag D tag al ate the device is
nder a co n. Thi auto
ic (th co the state change requests written to the
ATE tag a nd al
e the opera es the REQ_STATE tag. OPC90 will receive the write
he st n writing
ste th TA
upd
suc
con
unm
state transition is reques
sta states along with a
doi
the
acc for the
Exception Report Output Max Time setting of the block. When this occurs, bad quality will
also be written to the CIU and therefore propagated to the users of the block data within the
ABB Bailey system. The quality can also be set bad by writing a one (1) to this tag.
4.) The GOOD_STATE and REQ_STATE tags are used to indicate the actual (GOOD_STATE)
state of the device and its last requested state (REQ_STATE). The states are indicated as
numbers in the range of 0 through 3. By definition, the zero state is considered the default or
safe state of the device. States 1 through 3 are considered the operational states of a device
like slow, medium and fast. An operator re
REQ_STATE tag. Writing the REQ_STATE
indicates arriving at the requested state. The two tags not being equal and the ALARM tag
not being set indicate a travel condition.
pplication: The Bailey implementation of A
discrete ou used ntrol sign to a field dev
than two sta For ple a variable speed motor might
slow, medium d fast s. By defin tion, the MSDD has fo
These states ar the de
MSDD block ines th tput values f the three discrete outputs for each o
default state typically definethe four device states. For example the
outputs to
s the th
e first output set and the other two reet, sta could be th
and st t be al
except format lock has an OUT tag, which reports the outpu
of the first of three rete outputs This output is essentially useless f
included for compatibility with existing
y console uses the GOOD
REQ_STA s to d ine the act
e state to the GOOD_STATE ta
number 0 A reque for a device state occurs by a write to
REQ . The RE _TAG lows the client to indic
currently u red tag nditio s block supports mode. When in
mode, log e client) ntrols
REQ_ST with oper tor comma s to this tag being ignored. In manu
mod tor writ
request from t
e new reque
Bailey sy
d state to
em and tra
e REQ_S
sfer this request to the client by
TE tag. When the client detects a state th
change has been requested (GOOD_STATE <> REQ_STATE), the client must
ate the feedback tags (F1 through F4) and GOOD_STATE tag to reflect
cessful arrival of the device at the requested state. If feedback cannot be
firm, the client must set the ALARM tag and leave the GOOD_STATE
odified. Likewise, the client must reset the ALARM flag when a new device
ted and only set it again if feedback cannot be
confirmed. The Bailey implementation of the MSDD block defines the required
tes of the feedback signals for the four possible device
feedback wait time. The feedback wait time is the amount of time to wait before
ng feedback confirmation for the requested new state. Therefore, a delay in
setting the ALARM tag, by the client when feedback is not confirmed is
eptable. The client must also set the ALARM tag if good feedback
The RoviSys Company Version 7.0 Page 92
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