LeCroy 8901A Operator's Manual page 7

PRODUCT DESCRIPTION
GENERAL
The Model 8901A is a CAMAC module which provides GPIB
access to a CAMAC mainframe.
CAMAC is an international standard for modularized instrumen
tation as defined by the ESONE Committee and the IEEE
(Standard #583). Its function is to provide a means by which a
wide range of modular instruments can be powered in a multi-
receptacle crate and interfaced to a computer. The LeCroy
Model 8901A CAMAC to GPIB (IEEE 488) interface allows
the CAMAC system configuration to be used with GPIB com
puter controllers. For additional information on the IEEE 583
CAMAC standard, See Chapter 6.
Simple program instructions via the GPIB to registers in the
Model 8901A select an individual instrument module within the
CAMAC mainframe, select any subaddress within that module,
and establish the function (read, write, control). This allows
the user to handle the entire CAMAC mainframe of up to 23
individual instrument modules in the same manner as any ordi
nary single device connected to the IEEE-488 bus. It is possi
ble to interconnect up to 15 different CAMAC mainframes in
this way.
The 8901A can be programmed to do a block transfer of all
data within a CAMAC module to a GPIB Listener without addi
tional intermediate commands. In this mode, the 8901A will
alternately transfer one, two or three 8-bit bytes (as pro
grammed) as fast as the Listener can accept them (at rates ap
proaching 500 kilobytes/sec) and then initiate a new CAMAC
acquisition cycle.
The Model 8901A is a direct replacement for both the LeCroy
Model 8901 and 8901/100 (Mod 100) and will work with
LeCroy 6900 series CATALYST software. In addition to all of
the 8901-8901/100 features, the "A" version includes the gen
eration of the GPIB EOI signal at the end of valid data, a
jumper to select the order in which data bytes are sent to the
GPIB controller, and a "slow" block mode transfer for instru
ments that cannot be read out at full CAMAC speed.
SPECIFICATIONS
Internal Registers
Registers in the 8901A Interface are sequentially loaded with
data after it has been commanded to enter the Listen mode by
the GPIB System Controller. These registers store all the infor
mation necessary (F, A, N, W, C, Z, I) to generate standard
CAMAC cycles.
The first^byt^received by the interface after it has entered the
Listen mode contains either the CAMAC Function (F Code) or