ONGC_GCS_Ramnad

Red :- Error LED, should be off obviously

Yellow one each for Ports 1 & 2:- off:- Port disabled

Flashing:- No configuration/port communicating, but faulty fieldbus device

The FF powersupply also has red error LED for module failure.
The diagnostic module has 4 amber LEDs to indicate the status of 4 Field Barriers.

 H1 fieldbus technology is modelled on OSI and has Physical layer, Communication layer and Application layer. 16 FF devices are supported on each segment.
The communication layer is made of Data Link layer, Fieldbus Access Sublayer and Fieldbus Message specification.  Data Link layer controls the transmission of messages on fieldbus segment
 

The H1 card functions as the Link Active Schduler (LAS) in communication layer. Some of its functions are:-

(1) Scheduled transfers (2) Unscheduled transfers (3) Maintaining Live list

(1) Scheduled Transfer
Compel Data Schedule in Scheduled transfers
Scheduled transfers are regular in nature and LAS maintains a schedule of devices called COMPEL DATA SCHEDULE . Each device has its buffer and compel messages go out from the LAS to each device cyclically. The device responds from its buffer. The devices which are configured to receive the response are called subscribers.

link from function block of controller to function block of device- publisher VCR

link from function block of device to controller- subscriber VCR

link from function block of device to function block of device- subscriber VCR

output link-> publisher, input link-> subscriber

H1 card supports 35 publisher (o/p) VCR and 50 subscriber (i/p) VCR per port and total number of VCR should not exceed 50. If a Backup link scheduler is provisioned in the link, it should be able to provision for required VCRs else backup link master will not work.

Some devices have Free VCRs, these VCRs can function as publisher, subscriber or device alarm.

(2) Unscheduled Transfer
User initiated changes such as setpoint changes, tuning changes and downloads are carried out as LAS gives all devices a chance to send unscheduled messages between transmission of scheduled messages by way of issuing a Pass Token (PT) <which circulates in the segment>.The LAS maintains a list of devices , this list is called LIVE LIST. when device receives a PT, it sends unscheduled messages until it has finished or token hold time timeout is reached.

(3) Maintaining LIVE LIST.
A device can be added anytime to the segment. Between the times, it sends compel messages, The LAS sends PROBE NODE (PN) messages to devices not  in the live list. The device responds with a PROBE RESPONSE (PR) message and gets added to LIVE LIST.

 

5.3 REPLACING A FF TRANSMITER
1. In delta V explorer, browse the FF I/O card and rt click the particular device and click on decommission. The device appears in the decommissioned nodes. Rt click and click standby to change the state.
2. Delete the placeholder for the device.(say the tag name was FT-4001)
3. Connect the new transmitter in the field. It appears in the decommissioned devices
4. Create a new placeholder with same Tag name  FT-4001
5. Drag n drop from the decommissioned device to this placeholder
6. If DD (Device Descriptor) files are existing for this transmitter, follow the wizard steps to commission the device. Else, download the DD files from Emerson website and add it to the Library. One of the files should have a .fhx extension , else it will not be loaded in Delta V environment. Download the file for the correct version of device, delta v and AMS. The delta v download site is user friendly and can search for all these parameters easily.
7. Repeat step6 and complete the wizard. Download the newly created placeholder FT-4001
8. In the controller node, check the modules which use this AI, rt click and assign AI to the newly created FT-4001 to these modules.
9. Download the Modules
10. Open the AMS device manager and perform the necessary re-ranging of transmitter.