Femto Amplifier Support

SNL-Based Driver (femto.st)
Transform-Based Drivers (femto_DxPCA_x00)
- Macros
- Substitution File Example

Support for Femto brand low-noise current amplifiers. Two independent driver approaches are available in the std module.

SNL-Based Driver (`femto.st`)

The State Notation Language program femto.st controls Femto DLPCA-200 amplifiers by translating a gain index (0-14) to the appropriate combination of digital output bits. It supports both high-speed and low-noise modes.

Gain Table (DLPCA-200)

Index	Gain (V/A)	Mode
0	10^3	High Speed
1	10^4	High Speed
2	10^5	High Speed
3	10^6	High Speed
4	10^7	High Speed
5	10^8	High Speed
6	10^9	High Speed
7	10^3	Low Noise
8	10^4	Low Noise
9	10^5	Low Noise
10	10^6	Low Noise
11	10^7	Low Noise
12	10^8	Low Noise
13	10^9	Low Noise
14	10^9	Low Noise

Database

femto.db provides the following records:

Record Name	Type	Purpose
`$(P)$(H)$(F):Level`	mbbo	Gain index selection (0-14)
`$(P)$(H)$(F):Gain`	ao	Gain value in V/A
`$(P)$(H)$(F):Name`	stringout	Amplifier description

Loading with femto.iocsh

The simplest way to load the SNL-based femto support is with the iocsh script:

iocshLoad("$(STD)/iocsh/femto.iocsh", "PREFIX=xxx:, HARDWARE=A1, FUNC=femto, G1_PV=xxx:Unidig1Bo0, G2_PV=xxx:Unidig1Bo1, G3_PV=xxx:Unidig1Bo2, NO_PV=xxx:Unidig1Bo3, STD=$(STD)")

Loading Manually

dbLoadRecords("$(STD)/stdApp/Db/femto.db", "P=xxx:,H=A1,F=femto,G1=xxx:Unidig1Bo0,G2=xxx:Unidig1Bo1,G3=xxx:Unidig1Bo2,NO=xxx:Unidig1Bo3")
doAfterIocInit("seq &femto, 'P=xxx:,H=A1,F=femto,G1=xxx:Unidig1Bo0,G2=xxx:Unidig1Bo1,G3=xxx:Unidig1Bo2,NO=xxx:Unidig1Bo3'")

Transform-Based Drivers (`femto_DxPCA_x00`)

An alternative set of drivers uses transform records for gain control instead of a State Notation Language program. These drivers are independent of the SNL-based driver above.

Model-specific database files are available:

File	Model
`femto_DDPCA_300.db`	Femto DDPCA-300
`femto_DHPCA_100.db`	Femto DHPCA-100
`femto_DLPCA_200.db`	Femto DLPCA-200

Macros

The macros specify which digital output PVs control each function:

Macro	Description	Used By
`P`	PV prefix	All models
`A`	Amplifier name	All models
`G1`	Gain first (lowest) bit PV	All models
`G2`	Gain second bit PV	All models
`G3`	Gain third bit PV	All models
`G4`	Gain fourth bit PV	DDPCA-300 only
`SN`	High speed / Low noise bit PV	DHPCA-100, DLPCA-200
`C`	Coupling PV	DHPCA-100, DLPCA-200
`F10`	10 MHz Filter PV	DHPCA-100 only
`F1`	1 MHz Filter PV	DHPCA-100 only

Substitution File Example

Create a substitution file (e.g., femto_DxPCA_x00.substitutions) to load the appropriate database for your amplifier model:

# Uncomment the femto amplifier you want to use.

#file "$(STD)/stdApp/Db/femto_DDPCA_300.db"
#{
#pattern
#{P       A       G1          G2          G3          G4         }
#{crate:  femto1  Unidig1Bo0  Unidig1Bo1  Unidig1Bo2  Unidig1Bo3 }
#}

#file "$(STD)/stdApp/Db/femto_DLPCA_200.db"
#{
#pattern
#{P       A       G1          G2          G3          SN          C          }
#{crate:  femto2  Unidig1Bo4  Unidig1Bo5  Unidig1Bo6  Unidig1Bo7  Unidig1Bo8 }
#}

#file "$(STD)/stdApp/Db/femto_DHPCA_100.db"
#{
#pattern
#{P       A       G1          G2           G3           SN           C            F10          F1          }
#{crate:  femto3  Unidig1Bo9  Unidig1Bo10  Unidig1Bo11  Unidig1Bo12  Unidig1Bo13  Unidig1Bo14  Unidig1Bo15 }
#}