STATUS A MODULE

			CERN-EP type 155


1.  GENERAL

	This single width CAMAC module was designed to act as an inter-
face for control-, status-, busy-, and similar signals to be transferred
between the experimental set up and the computer-CAMAC complex.

	It consists of five channels with individual frontpanel input
and output Lemo connectors.  Each channel can also be set/reset by CAMAC
commands.
	                                              ____
	There are two common outputs, called BUSY and BUSY, which can
be activated by one or more of the channels.  All these features are
controlled by a command Mask register.

2.  DESCRIPTION OF THE MODULE

   2.1	The Circuit

	The heart of each channel is a flip-flop which can be set either
by the frontpanel input or be the appropriate CAMAC command (see para. 4).
The frontpanel input is active only if the corresponding bit in the mask-
register (bits 1-5) is set to logical "1".  The reset is done by CAMAC
commands, either channel by channel or all together as described in para 4.

	The output of the flip-flop is used in many different ways; it
goes:

a)  directly to the corresponding front panel output,

b)  to the corresponding Read-line gated with the Read-command (see para 4),
                           ____
c)  to the common BUSY and BUSY output if enabled by the maskregister
    (bits 11-15),

d)  to the LAM-line if enabled by the maskregister (bits 6-10).

	The state of each individual channel can be tested by executing
N·F8·Ay which gives Q = 1 if the channel is set and its LAM output is
enabled.

   2.2	Front panel inputs

	a)  Inputs 1 to 4

	    These channels accept as input (to set the channel) a
standard NIM-pulse (-16 mA) with a width of >= 5 nsec.

	b)  Input 5

	    The channel 5 is set by a frontpanel pushbutton.

   2.3	 Frontpanel outputs

	a)  Outputs 1 to 5

	    Standard NIM output (-16 mA) that will be active whenever
the corresponding channel is set.  Propagation delay from frontpanel
input to the corresponding output is <= 10 nsec.
	             ____
	b)  BUSY and BUSY

____	    Standard NIM output (-16 mA).  The BUSY, and its complement
BUSY, can be set by any channel with the Busy feature enabled by the 
maskregister.  Propagation delay from frontpanel input to BUSY or BUSY
output is <= 15 nsec.


3.  MASKREGISTER

	The maskregister controls all features in the module and the bit
assignment is as follows:

	Bit 1	Enable frontpanel input channel 1
	 "  2	   "       "        "      "    2
	 "  3	   "       "        "      "    3
	 "  4	   "       "        "      "    4
	 "  5	   "       "        "      "    5

	 "  6	Enable LAM to be generated by channel 1
	 "  7	   "    "   "  "     "      "    "    2
	 "  8	   "    "   "  "     "      "    "    3
	 "  9	   "    "   "  "     "      "    "    4
	 " 10	   "    "   "  "     "      "    "    5
	                    ____
	 " 11	Enable BUSY/BUSY to be generated by channel 1
	 " 12	   "       "      "  "     "      "    "    2
	 " 13	   "       "      "  "     "      "    "    3
	 " 14	   "       "      "  "     "      "    "    4
	 " 15	   "       "      "  "     "      "    "    5

	 " 16	                  not used

	The feature in question will be enabled when the corresponding
bit is set to logical "1".  The register can be accessed by read and write
commands as defined in para. 4.

4.  CAMAC Commands

	N·F1·A0    Read Maskregister
	           [Q = 1; X = 1]

	N·F1·A12   Read channel pattern, (ch.1 -> bit 1 ... ch.5 -> bit 5)
	           [Q = 1; X = 1]

	N·F8·Ay    Test LAM from channel number (y + 1)
	           [Q = 1 if set and LAM enabled; X = 1]

	N·F10·Ay   Reset channel (y + 1)
	           [Q = 1; X = 1]

	N·F11·A12  Reset all channels
	           [Q = 1; X = 1]

	N·F17·A0   Write into maskregister
	           [Q = 1; X = 1]

	N·F25·Ay   Set channel number (y + 1)
	           [Q = 1; X = 1]

	   Z       Reset all channels and clear maskregister

A scanned manual is located here.