Hello,
I have configured iFix 5.8 SCADA to work with Siemens S7-400 PLC over Siemens TCP/IP Ethernet IGS v7 driver.
I have 2 channels with 4 devices on each channel.
On IGS driver side I use dynamic approach (no IGS static tags).
On IGS devices I have set Respect client specific scan rate and default Timing options.
In IGS project properties I unchecked Enable Latched Data.
All devices on same channel are configured identically (almost all default settings).
In normal operation everything works as expected.
Problem occurs when I disconnect PLC cable from network, SCADA animations start turning red (indicating comm. loss) after a minute or two, and gradually (device per device) indicating comm. loss. Overall, it takes too long time to indicate comm. loss.
Problem is that iFix PDB is still getting last known data from IGS driver (even though Latched data is not enabled) for a long period of time.
IGS logs when PLC comm. is lost:
<remark: PLC cable unplugged: 16:48:18>
16.4.2015 16:38:20 Warning Siemens TCP/IP Ethernet Device 'PLC31.P31_2' with ID 172.17.145.203 is not responding.
<remark: SCADA objects with tags on this device turned red>
16.4.2015 16:38:24 Warning Siemens TCP/IP Ethernet Device 'PLC31.P31_1' with ID 172.17.145.203 is not responding.
<remark: SCADA objects with tags on this device turned red>
16.4.2015 16:39:42 Warning Siemens TCP/IP Ethernet Device 'PLC31.P31_3' with ID 172.17.145.203 is not responding.
<remark: SCADA objects with tags on this device turned red>
16.4.2015 16:42:48 Warning Siemens TCP/IP Ethernet Device 'PLC31.P31' with ID 172.17.145.203 is not responding.
<remark: SCADA objects with tags on this device are left in last known state and gradually in a period of 10 minutes turned red or ????, until Device goes to error state>
Order in which devices loose communication is always different as well as com. loss indication on SCADA.
Also, device internal tags _Error does not indicate comm. loss immediately.
What I noticed is, when device _Error state is 0, SCADA is getting last known value from driver.
This Error state is not acting as supposed.
If I disconnect cable from SCADA server, SCADA animations turns red immediately.
It seems like problem on driver side, SCADA PDB is just reading the data from driver.
Is there a way to indicate comm. loss immediately?