Difference between revisions of "VDC HV control"

Revision as of 15:25, 29 March 2017

Relay Box with 8 relays (channels) controlled by RPi board is used to limit trip current and prevent trips for VDC high voltage line during HV on/off operation.

Two of them have been installed in Left and Right HRS at the end of March, 2017.

• Left HRS:

  name: rpileft 
  IP: 129.57.164.27
  passwd: same as for rpi8

• Right HRS:

  name: rpiright 
  IP: 129.57.164.53
  passwd: same as for rpi7

Relay box consists of 8 relays and 8 resistors with 68Mohm nominal. Resistor is connected in series between output of hv channel and VDC hv line, or shortened by relay.

RPi board is used as TCP/IP server to control relays by commands from clients. RPi board in HV crate (rpi8(left), rpi7(right)) runs 'shim-server' to control modules in crate.

Shim-server will send commands to relay box server to switch relay ON (closed, shortened resistor) or OFF (open, resistor in).

Shim-server checks commands/responses from GUI to hv channel that connected to VDC. The next logic will be used by shim-server to control relays :

• commands: HVON, HVOFF, demand voltage (DV) set, enable/disable channel (CE), channels status (ST>1) ---> relay is OFF (open, resistor in) for this channel.
• channels status (ST==1) --> relay is ON (closed, resistor out) for this channel.

Command format for relay box server is the same as used by LeCroy HV system (examples):

• set relay channel #1 to ON (closed)

LD S0.1 RLY 1

• set relay channels #0,#2 to ON (closed) and channels #1,#3-#7 to OFF (open)

LD S0 RLY 1 0 1 0 0 0 0 0

• get status of all relays channel (1 - is ON, 0 - is OFF)

RC S0 RLY

Hv module for VDC will have one more property column 'RLY_en' in Java GUI, that shows status of relay box channels (0 - relay is OFF, 1 - relay is ON).