NAME

dlb − dial box

DESCRIPTION

dlb controls the Stardent 1500/3000 digit-8 dial box which is made by Honeywell.  dlb is a STREAMS module, pushed on top of an RS-232 line driver. 

The user can not send data to the dial box, but can receive data.  The data are encapsulated in the structure gin format as defined in <machine/gin.h> before being sent toward the user. 

struct gin {
unsigned longgin_msec;
unsigned longgin_mux_id;
unsigned shortgin_id;
chargin_dev;
chargin_dim;
longgin_buttons;
shortgin_data[NDIM_GIN];
};

gin_id is GID_DIALS.  gin_dev is GDEV_REL|GDEV_SUBDEV.  gin_dim is two (2).  gin_buttons is zero (0).  The first data (gin_data[0]) indicates which dial (value from 0 to 7).  The second data (gin_data[1]) specifies the relative movement (delta) for that dial (value 0 to 255). 

For the standard configuration, the dial box is connected to the serial port “d” (that is, tty line 3).  Thus, /dev/dials is linked to /dev/tty3.  The user conventionally opens /dev/dials, (via open(2)), pops off the tty line discipline, (via I_POP ioctl), and pushes the dlb(7) module, (via I_PUSH ioctl). 

COMMAND FUNCTIONS

dlb(7) recognizes the following ioctl commands.  The argument (the M_DATA block following the M_IOCTL) has the format of the structure ginioctl, defined in <machine/gin.h>:

struct ginioctl {
intg_cmd;
intg_id; /∗ muxid under gin ∗/
intg_arg1;
};

G_MSTHRESH Set the threshold (delta) value which must be exceeded before the delta value is reported to the user.  All eight (8) dials are set to the same value, a 32-bit integer.  The default threshold is 1. 

G_MGTHRESH Retrieve the threshold value. 

G_RATE Set the rate at which data packets are transmitted to the user.  g_arg1 specifies the rate in samples per second.  Default is 20 samples per second. 

FILES

/dev/dials

SEE ALSO

streamio(7), gin(7)
DIGIT Technical Specification, Honeywell. 

September 29, 2021