IEEE 675-1982 pdf free.IEEE Standard Multiple Controllers in a CAMAC Crate.
IEEE 675 defines a method for incorporating more than one source of control into a CAMAC crate.The standardfully conforms to the mechanical and signal standards of the CAMAC system as described in ANSIIEEE Std 583-1982, Modular Instrumentation and Digital Interface System(CAMAC), or EUR 4100e.
In order to allow more than one Controller to access the Dataway of a CAMAC Crate, anAuxiliary Controller Bus(ACB)and priority arbitration protocol are fully defined.This permits the use of Auxiliary Controllers (ACs) in normalstations in the crate. The ACB carries encoded address information from an AC to the Crate Controller (CC) in thecontrol station of a CAMAC crate, and carries Look-at-Me signals from the CC to the ACs. The ACB, connectedbetween controllers,may also be used to establish priority for control of the CAMAC Dataway.
This standard is fully compatible with ANSIIEEE Std 595-1982, Serial Highway Interface System(CAMAC), orEUR 6100e, and the ANSIIEEE Std 596-1982, Parallel Highway Interface System(CAMAC) or EUR 4600e. It mayalso be used in autonomous systems (systems with no external highways) or in systems with Type UCrate Controllers(such as systems with a computer I/O bus as the highway).
Section A of the Appendix to this standard defines a Parallel Highway Crate Controller,Type A-2.This controller issimilar to Crate Controller Type A-1 (as defined in Section A of the Appendix to ANSIIEEE Std 596-1982 or EUR4600e), except for the ACB connector and the priority arbitration protocol. When these two features are not required,Crate Controllers Types A-1 and A-2 are totally interchangeable.
This standard is a reference text describing and specifying multisource control within a CAMAC crate. It should beread in conjunction with, and is supplementary to,ANSIIEEE Std 583-1982,ANSIIEEE Std 595-1982, and ANSI/IEEE Std 596-1982 or EUR 4100e,EUR 6100e, and EUR 46003, respectively.The standard CAMAC crate, described in ANSVIEEE Std 583-1982 or EUR 4100e requires the presence of aController to control and coordinate the activities of the crate. During a Dataway addressed command operation, theController establishes the necessary signals on the B,N,A, F, S1, and S2 lines to define the command operation to beperformed and to define the timing of the operation. During addressed command operations involving data，theController transmits or receives data via the W or R lines, respectively. During unaddressed operations, the Controllerestablishes the necessary signals on the B,S1,S2, and C or Zlines.The Controller may establish the state of the lsignaland may monitor the state of the L, X, and Q signals.
Each CAMAC crate has one control station, which is the only station providing access to the N and Llines.The controlstation and a normal station together provide access to all signal lines needed by aController to perform the operationsdescribed above.The Controller which occupies the control station is designated theCC of the crate. Examples of CCsare the Serial Highway Crate Controller Type L-2(Section Al of the Appendix of ANSIIEEE Std 595-1982 or EUR6100e) and the Parallel Highway Crate Controller Type A-2(Section A1 of the Appendix of this standard).
An additional source of control within a CAMAC crate can be provided by an AC, which occupies one or more normalstations In order to accommodate ACs, two features are required:(1) access to the N and L lines at normal stations, and(2) priority arbitration for control of the Dataway. Access to the N lines is necessary to allow an AC to generate acomplete addressed command operation.Access to the L lines is necessary if an AC is to respond to Look-at-Mesignals from other modules or controllers, or both. Priority arbitration protocol ensures that at any time only oneController is permitted to have control of the crate. It also provides the means for assigning control of the Dataway onthe basis of a prearranged priority.IEEE 675 pdf download.