Jcop testbench Caen SY127 HV power supply OPC Server: A short tutorial
The goal of this tutorial is not to explain all the items of the OPC Server,
neither to explain the Caen Power Supply use. It just attempts to
give the minimum information to use this OPC Server.
Crate configuration
The SY127 can have up to 10 cards of 4 channels each. In the SY127 of the
jcop testbench 3 cards are installed. The numbers of the used channels
are: 00,01,02,...11.
The OPC client
To access to the OPC Server you have to use an OPC client. You can use
National Instrument Server Explorer which is installed on the PC, BridgeView
(also installed), a SCADA... A demo vi file to use with BridgeView is in
the folder D:\CAEN SY127 HV OPC Server.
The Name of the Server to connect to is: OPCCaenHV.
Settings
Voltage
The Voltage is set, in volts, through the item
"cr02.chyy.V0", where yy is the number of the channel, e.g.
01.
Maximum current
The current upper limit is set, in milliamps, through the item "cr02.chyy.I0".
Trip delay
The trip delay is set, in seconds, through the item
"cr02.chyy.TripD". For example if cr02.ch00.TripD is set to
1.1 and the maximum current has been reached for 1.1 second then the High
voltage is shut down, the power supply gets to trip state, an alarm is
generated. To acknowledge the trip alarm you have to write on the item
cr02.ClrAlrm (doesn't work with BridgeView but works with ServerExplorer).
Ramp-up/down slow rate
The ramp-up slow rate is set, in V/s, through the item "cr02.chyy.RupS",
the ramp-down slow rate through "cr02.chyy.RdwnS".
Channel On/Off
Channel yy is put on or off through the item "cr02.chyy.On".
TRUE (i.e. different of 0) for on, FALSE (i.e. equal to 0) for off.
Monitoring
Voltage
The monitored voltage is read, in volts, through the item "cr02.chyy.Vmon".
Current
The monitored current is read, in milliamps, through the item "cr02.chyy.Imon".
Channel status
The channel status can be read through the byte item cr02.chyy.Status
or through the following boolean items:
-
cr02.chyy.Rdwn: the voltage is going
down. Equivalent to bit 7 of cr02.chyy.Status
-
cr02.chyy.Rup: the voltage is going
up. Equivalent to bit 6 of cr02.chyy.Status
-
cr02.chyy.OVI: over-current. Equivalent
to bit 5 of cr02.chyy.Status
-
cr02.chyy.UNV: the monitored voltage
is under the voltage setting. Equivalent to bit 4 of cr02.chyy.Status
-
cr02.chyy.OVV: the monitored voltage
is over the voltage setting. Equivalent to bit 4 of cr02.chyy.Status
-
cr02.chyy.On: TRUE (i.e. different
of 0) if the channel is on. Equivalent to bit 2 of cr02.chyy.Status, reverse
of bit 0 of cr02.chyy.Status.
Crate status
In the crate status what can be useful is the HV enable flag which indicates
if the High Voltage is Enabled. the corresponding item is "cr02.HVENBL".
It is set to TRUE (i.e. different of 0) if HV is enabled.
Commands
There is nothing foreseen in OPC to send to the device a command. The only
thing you can do is writing on an item or reading an item. So We decided
that to send a command we will write on an empty item. An empty item is
an item that contains no value (VT_EMPTY variant type). But BridgeView
seems to not support empty items. This will be a good test to see if evaluated
SCADA supports this kind of items. The National Instrument Server explorer
does.
One command of the SY127 OPC Server which is useful is the clear alarm.
It is used to acknowledge alarms as trip. The item is cr02.ClrAlrm.
revised on May, 27 1999