4.6.2 Modbus Status Registers

Starting at Modbus Register 00001 the IO-FEP2 offers a compact block of registers containing all volatile status information. An M&C application may acquire these effectively with a block read command.

  Register    Purpose               Remarks

  00000       reserved              for internal use
                          
  00001       inputs 1..16          see 'Input Port Status
  00002       inputs 17..32         Encoding' below.
  00003       inputs 33..48
  00004       inputs 49..64

  00005       wg-sw 1..8 state      see 'WG Switch Status Encoding'
  00006       wg-sw 9..16 state     below.
  00007       wg-sw 17..24 state
  00008       wg-sw 25..32 state

  00009       wg-sw 1..8 alarm      see 'WG Switch Alarm Encoding'
  00010       wg-sw 9..16 alarm     below.
  00011       wg-sw 17..24 alarm
  00012       wg-sw 25..32 alarm
  
  00013       power supply alarm    bit 0: redundant 24V ext fault
                                    bit 1: redundant 24V fault
                                    bit 2: primary 24V ext fault
                                    bit 3: primary 24V fault    
                                    bit 4: LNA supply 1 fault
                                    bit 5: LNA supply 2 fault
                                    bit 6: 5V fault
                                    bit 7: 3.3V fault
                                    bit 8: USB stick fault
                                    
  00014       temperature alarm     bit 0: 1 = board temp. high
                                    bit 1: 1 = sensor 1 high
                                    bit 2: 1 = sensor 2 high
                                    bit 3: 1 = sensor 3 high
                                    bit 4: 1 = sensor 4 high
                                    bit 8: 1 = board temp. low
                                    bit 9: 1 = sensor 1 low
                                    bit 10: 1 = sensor 2 low
                                    bit 11: 1 = sensor 3 low
                                    bit 12: 1 = sensor 4 low

  00015       prot-sw 1 state       see 'Protection Switch Status
  00016       prot-sw 2 state       Encoding' below
  ...         ...
  00045       prot-sw 31 state
  00046       prot-sw 32 state

  00047       lna 1 voltage         6 measured LNA supply voltages,
  ...         ...                   unsigned integer in steps
  00052       lna 6 voltage         of 0.01V

  00053       lna 1 current         6 measured LNS supply currents,
  ...         ...                   unsigned integer in steps
  00058       lna 6 current         of 0.1mA

  00059       lna 1 faults          6 sets of LNA monitoring faults
  ...         ...                   see 'LNA Monitoring Faults'
  00064       lna 6 faults          below
  
  00065       board temperature     Temperature values are reported
  00066       temp. sensor 1        as 16 bit signed integers, 
  00067       temp. sensor 2        scaled to 1/10 centigrades. A
  00068       temp. sensor 3        value of '-125' reports a 
  00069       temp. sensor 4        temperature reading '-12.5°C'

  00070       time sync alarms      enumerated integer:
                                    0 = sync ok or disabled
                                    1 = time not synced, fault.
                                    2 = synced to secondary NTP
                                        server, primary failed.

  00071       time sync source      enumerated integer:
                                    0 = RTC
                                    1 = first NTP server
                                    2 = backup NTP server

  00072       last time sync        time stamp of the latest clock
  ...                               synchronisation. 19 characters,
  00081                             YYYY-MM-DD HH:MM:SS format,
                                    0-terminated

Input Port Status Encoding The registers '1'..'4' report the state of the 64 configurable inputs of the IO-FEP2. The least significant bit of register '0' corresponds to input 1. A bit set to '1' reports an 'ON' or 'FLT' input, inputs which are 'OK' or 'OFF' read '0'.

The reported port states are logical states, they already include the polarity inversion and filtering delay as defined in the setup for each individual port. Unused ports and port which are not licensed always read '0'.

WG Switch Status Encoding Each switch encodes it's state in two bits of the number, WG switch 1 uses the least significant bits. The bits reflect the state of the position indication circuits of each switch:

'01' tells that the switch is in position 'A', '10' signals position 'B'. The bit combinations '00' and '11' both signal invalid states, a software monitoring the IO-FEP2 should decode this and report it to the operator.

The switch positions reported here are pre-processed by the IO-FEP2, not the raw position indication readings. If a switch is commanded to position 'X', this position is reported immediately, even if the switch did not yet reach this position. After the switch process has completed (or timed out) the real position is reported. This behaviour is necessary to hide the delayed / queued switching performed by the IO-FEP2 from a M&C computer which expects the IO-FEP2 to be a 'dumb PLC'. Unused waveguide switches and switches which are not licensed always report '00'.

WG Switch Fault Encoding Each WG switch reports two fault bits, one register contains the fault bits for 8 switches. Switch 1 reports its fault with the least significant bits.

The lower significant bit for a switch is set if there is an 'indication fault', if either both indication inputs read the same level.

The higher significant bit for a switch is set if there is an 'actuation fault', if the switch has been commanded and does not reach the commanded position within the pulse duration.

Protection Switch Status Encoding The protection switch units in the IO-FEP2 report their state as a bit combination in one register for each protection switch unit.

For each protection switch eight status bits are defined:

  bit 0 (lsb)   1 = WG-Switch fault or instance not configured
  bit 1         0 = 1:1-SW-ONCE, 1 = 1:1-SW-ALWAYS
  bit 2         0 = DISABLED, 1 = ENABLED
  bit 3         0 = 1:1, 1 = 2:1 redundancy (bit 1 doesn't care in 
                this case)
  bit 4         1 = fault in chain A
  bit 5         1 = fault in chain B
  bit 6         1 = SWITCHED
  bit 7         0 = chain A selected, 1 = chain B selected
  bit 8         bits 8 .. 15 are reserved for future use
  ...
  bit 15 (msb)

Unused protection switches report all bits set to 0. If protection switching is not licensed, all protection switches report 0 here.

LNA Monitoring Faults

There is one register for each LNA power supply monitoring channel which reports the fault states for this channel as a combination of the following bit definitions:

  bit 0 (lsb)   1 = voltage too low (shortcut or supply input 
                    missing)
  bit 1         1 = current too low (cable broken or LNA defective)
  bit 2         1 = current too high (shortcut or LNA defective)
  bit 3         bits 3 to 15 are reserved for future use, actually
  ..            all read 0
  bit 15 (msb)

If LNA power supply monitoring is not licensed, all fault bits read 0, also all measurement readings are clamped to 0