BPM Data Format

Contents

BPM Data Format

File Structure

6 bytes	size bytes
Packet Header	Packet Data Blocks
Packet Header	Packet Data Blocks
Packet Header	Packet Data Blocks
...	...

The file consists of packets. Each packet starts with header, contained packet data block type and its length of data with header and payload. Header specifies the type of data block and packet size.

Packet Header

offset	size, bytes	type	name	description
0	4	int	ID	block Type Id
4	4	int	size	packet size, bytes, including header

Packet Data Blocks

There are four types of data blocks:

Main Block
Device Description Block
Start/Trigger Description Block
Event Description Block

Main (Type Id: 1)

offset	size, bytes	type	name	description
0	4	uint	timeStamp	[32bit time_t] Event time in sec from 1 Jan 1970 (UTC)
4	8	double	BField_B0	BField_B0, Tesla
12	8	double	BField_step	BField_step, Tesla/step
20	8	double	BField_drift	BField_drift, Tesla/sec
28	4	uint	particleCharge	Particle charge
32	8	double	particleMass	Particle mass, eV
40	8	double	NuclotronCircumference	Closed orbit length, m
48	4	uint	NuclotronKf	RF harmonic number
52	8	double	NuclotronRho	...
60	4	int	master_id	Id of master box
64	4	uint	sampleSize	Sample size of adc

Start/Trigger Description (Type Id: 2)

offset	size, bytes	type	name	description
0	4	int	start	Type of start
4	4	int	trigger	Type of trigger
8	8*8	double[8]	array	Trigger array

If trigger type is 'B Field': trigger array contains values on which this should enabled. If trigger type is 'Time': trigger array contains time in ms on which this should enabled. If trigger type is 'Periodic': first value in trigger array contains periodic delay, second one period length, others are unused.

Device Description (Type Id: 3)

offset	size, bytes	type	name	description
0	4	uint	id	Device Id
4	4	uint	serial	Device serial number
8	8	double	temp	Temperature in C
16	8	double	clock	Clock tics over the last second
24	4	uint	firmware_ver	Firmware version
28	4	uint	firmware_rev	Firmware revision
32	4	uint	eventNumbers	Number of events from this box
36	8	long long	timestampLastNCU	Clock ticks at start acceleration period
44	8	long long	timestampLastKCU	Clock ticks at end acceleration period

Event Description (Type Id: 4)

offset	size, bytes	type	name	description
0	4	uint	deviceId	Device serial number
4	4	uint	eventNumber	Event number
8	8	double	clock	Device clock ticks at event
16	4	int	BFieldTicks	B field ticks at event
20	24sampleSize	uint[]	adc	ADC

BPM Raw Event Format RawData Bpm4100