CAMAC CONTROLLER
MODEL 1502
TYPE L-2 SERIAL CRATE CONTROLLER

FEATURES Designed to CAMAC Specifications IEEE 583 and 595 Max. of 62 Crates on Serial Loop Optional test points on front panel for Clock and Data Crate address selection via front panel switch Serial clock rates to 5 megabits per second Bit or Byte Mode of Operation Asynchronous Demand Generation Magnetically Shielded Relays APPLICATIONS CAMAC Standard Type L-2 Serial Crate Controller Large distance between CAMAC crates in a Serial Loop Configuration Operations with any standard CAMAC Serial Driver Operates in 50 gauss Magnetic Field Industrial Process Control

GENERAL DESCRIPTION
Bi Ra Model 1502 Type L-2 Serial Crate Controller complies fully with the CAMAC specifications. This double-width module is the CAMAC standard interface between the CAMAC Serial Highway and the crate dataway. This Model 1502 will operate with any standard serial driver (such as the Model 1401) and allows operation with up to 62 crates in a loop arrangement. The units may be directly cabled or linked with adapter modules and modems. The units can be operated in the Bit or Byte serial modes. The Bit serial mode allows for economical cabling between units, where as the Byte mode is ten times faster in operation. The units will operate up to 5MHz clock rates; the transmission medium may limit the maximum clock rate. The use of fiber optic adapters allow operation over longer distances and higher speeds than direct cabling between units.

DEMAND MESSAGE OPERATION
Model 1502 will generate demand messages in response to any LAM in the crate. The three Byte message is inserted between other messages on the serial highway. The unit will generate Repeat-Demand messages if the LAM is not cleared in a specified elapsed time. Delays from msec to ten seconds are switch selectable on the module. The repeat can be disabled with a strap on the module. The SGL connector is mounted on the rear of the module above the dataway and is the standard 2DB52P connector. The connector has all the signals necessary to operate the unit with the standard auxiliary controllers and to initiate demand messages.

STANDARD INTERNAL FUNCTION CODES (N=30) FOR MODEL 1502		NORMAL		OFFLINE		BYPASS
COMMANDS		SQ	SX	SQ	SX	SQ	SX
Read Status Register	N30 F1 AO RD2	1	1	1	1	1	0
Write Status Register	N30 F17AO WT2	1	1	1	1	1	Q*
Selective Set Status Register	N30 F19AO SS2	1	1	1	1	1	0
Selective Clear Status Register	N30 F23AO SC1	1	1	1	1	1	Q*
Reread Data Field	N30 FO A1 RD1	DSQ		DSQ	1	1	0
Read LAM pattern	N30 F1A12 RD2	1	1	0	0	1	0
Dataway command		Q	X	0	0	1	0
Error Reply	*X=1 for command to clear BYPASS	0	0	0	0	0	0

STATUS REGISTER ASSIGNMENTS

BIT	Write logic 1 into Register	Read Logic 1 from Register	State on Power Up
1	Generate Z	always 0	0
2	Generate C	always 0	0
3	Set I=1	lout = 1	1
4		DERR = 1	0
5		DSX =1	0
6		DSQ =1	0
7		Dataway I = 1	0
8	Reserved	always 0	0
9	Enable Demands	Demand Enable	0
10	Set Internal Demand L24	L24 =1	0
11	Collapse Loop	Loop Collapsed	1
12	Apply Bypass	always 0	1
13	Dataway off line	Dataway off line
14		Switch off line
15	Reserved	always 0
16		Selected LAM present

LOOP COLLAPSE AND BYPASS

Bits 11 and 12 of the status register control magnetically shielded relays in the SCC. The contacts of these relays control external Loop Collapse and Bypass hardware, via contacts in the D-ports connectors. The state of power-up or when crate power is removal are the same, the loop is not collapsed, and BYPASS has been applied.

FRONT PANEL CONNECTORS

The front panel serial highway connectors have contacts that allow control of external By-Pass and Loop Collapse devices. If power is lost in the crate, the By-Pass contact will close the Loop Collapse contact will open. The connectors have the standard configuration that allows connecting one serial cable to the OUT connector and installing a jumper connector in the IN connector. The optional auxiliary connector allows front panel access to clocks, Bit data signals, and module voltages.