characters or a negative sign “-”, the characters will be read until a terminating character (see
t.chr
) is found.
In circumstances, e.g. when terminating characters are not sent by the transmitting device, the instrument can be
programmed to look for a constant transmitted character which occurs before to the required display values rather
than at the end of the string. In this instance the
SCH1
character can be used and the display told to display a
number of characters after this character (see
N.Chr
function). Once the
t.chr
or
SCH1
character is found the
numeric value will be updated and displayed. If a non numeric character is found then the conversion will cease at
that point. Note that ASCII control characters 00 Decimal (Null) to 31 Decimal (Unit Separator) will be ignored if
they are seen as part of the string and will not cause the conversion to cease when encountered, they will however
not be ignored if used as a start character (
SCH1
,
2
or
3
) or the terminating character set at the
t.chr
function.
The numeric value is filtered after conversion the
FLtr
setting determines the level of filtering. Note: In
UAL
mode any leading zeroes transmitted will be ignored e.g. data received such as -00345 will be displayed as -345.
M.buS
mode
With
M.buS
selected the display will accept a Modbus RTU input (RS232 or RS485) or Modbus TCP (port 502)
with LE5 models. An address (1 to 255, do not use address 0) must be selected at the function to correspond to
the address selected at the host device. The instrument accepts Modbus command 6 “preset single register” and
command 16 “preset multiple registers” to send values to the display. The command 6 or 16 information sent can
be used to preset four registers, these are:
Register 0 Decimal point position (note
IN1 dPnt
function must be set to
Auto
if this register is to be used to
set the decimal point)
Register 1 Input taken as an unsigned 16 bit number (0 to 65535)
Register 2 Input taken as a signed 16 bit number (-32767 to 32767)
Register 3 Signed 32 bit number high order 16 bits
Register 4 Signed 32 bit number low order 16 bits
Registers 3 and 4 are used together to form a 32 bit number. The display will be updated when the low order register
is set.
For example to send the number 1234 to a display with address 1 using Modbus RTU function 6 the following could
be sent:
01 06 00 01 04 d2 5a 97
Where:
01 is the address set at the
IN1 Addr
function
06 is the function number 6
00 01 is the register number (register 1 unsigned 16 bit number)
04 d2 is 1234 in Hex
5a 97 is the system generated checksum
To poll for the display value via Modbus use address 0x1000 and 0x1001 hex, registers 44097 and 44098, Modbus
function 3. Modbus function 1 can be used to poll for relay coil status addresses 0x0000 to 0x0007, registers 1 to 8,
for relays 1 to 8 (4 relays fitted as standard, up to 8 relays are optionally available).
SCAN
mode
When
SCAN
is selected the display can scan up to 8 other compatible devices or channels. The address of each
device or channel, the display value required etc. must be set, these setting can be found in the
CH1
to
CH8
section
of software. When this mode is selected the channel number will flash followed by the value for that channel e.g.
CH 2
followed by the value returned for channel 2.
NMEA
mode
With
NMEA
selected the instrument must be connected to a sensor with standard NMEA output. In this mode the
decimal point
d.Pnt
function operates only on the speed display.
in131
mode
This is a special mode use when connected to a Mettler Toledo IND131/331 module. This mode examines special
status words sent by the device to determine the placement of decimal points and whether the value is positive or
negative. The standard decimal point functions in the PM5 display do not need to be used when connected in this
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