Honeywell PPT User Manual page 73

T O Transceiver Operating Parameters
Sets the Transceiver Operating parameters for the RS-232, or RS-485, transceiver interface proto-
col. The TO=R or
PPTs, or a multidrop configuration only for RS-485 type PPTs. All other command parameters apply
only to the multidrop RS-485 configuration. See Figure 4.19 for TO=A,
tions.
(Default: TO=R0CN for RS-232 type or
Inquiry: *ddTO
Action: *ddWE
*ddTO={R|M
*ddTO= {C|A|S|H} or *dd TO={N|P}
R
M
..............................................................................................................................
0-3
..............................................................................................................................
C
A
S
H
M commands can select either a ring
TO={0-3} or
} or *dd
Ring protocol for RS-232 units. This parameter option
485 type.
Multidrop protocol for RS-485 units. This option
requires an external RS-232 to RS-485 converter. If an RS-232 unit has TO=M
selected, then all the options labeled "RS-485 only" apply.
Controls the minimum command response delay, RS-485 bus turn around time. For
baud rate of 9600 and below, each count (0-3) represents about 1 millisecond. For
baud rates above 9600, each count represents one character transmission time. This
feature has no effect on RS-232 units.
Baud 1200
time/count 1 ms
Allows a RS-485 unit to transmit Continuous pressure readings (P2 or
device ID is used. This parameter has no effect on RS-232 units.
RS-485 only: Causes the SI command to start a pressure integration cycle and not
clear the result of the previous cycle so it can be read with a P2 or P4 command if
the result has not been previously read. When the synchronized cycle completes a
new cycle is immediately started.
RS-485 only: Causes the SI command to start a pressure integration cycle and clear
the result of the previous cycle so that a P2 or P4 command produces a "pressure
reading not available" indication (<cr> only) if a P2 or P4 read attempt is made
before the new integration cycle completes. When the synchronized cycle completes,
a new cycle is immediately started. If the pressure reading produced by the synchro-
nized cycle is to be read it must be read before the next integration cycle completes
RS-485 only: Causes the
the result of the previous cycle so that a P2 or P4 command produces a "pressure
reading not available indication" (<cr> only) if a P2 or P4 read attempt is made
before the new integration cycle completes. When the synchronized cycle completes,
the pressure reading is Held until it is read or until a new SI command is issued.
Setting: When an SI command is sent:
TO=C, or A Restart I= cycle
TO=S Restart I= cycle, Clear previous I= value
Restart I= cycle, Clear previous I= value, Stop after 1 I= cycle
T O = H
or multidrop configuration for RS-232 type
TO=M1CN for RS-485 type)
EEPROM Store: *ddWE
2400 4800 9600
1 ms 1 ms 1 ms
SI command to start a pressure integration cycle and clear
6 7
S, and H command illustra-
*ddSP=ALL
cannot be selected for the RS-
can be selected for RS-232 unit, but
14400 19200 28800
0.7 ms 0.5 ms 0.3 ms
P4) when the