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MODBUS SCT PPU

MODBUS SCT PPU

MODBUS SCT PPU communication protocol

Supported device types and versions

This protocol supports communication with the telemetric stations for remote measurement of gas by SCT company. It ensures the parallel measurement of data from the meters for wholesale and medium gas consumption of SPP-Distribúcia a.s.

Communication line configuration

Communication station configuration

  • Communication protocol "MODBUS SCT PPU".

  • The station address is a decimal number in the range of 0 to 255 (usually 1).

Station protocol parameters

Communication station - configuration dialog box - tab Protocol parameters.
These parameters influence some of the optional protocol parameters. You can define the following station parameters:

Table 1

Parameter

Meaning

Units

Default value

Retry Count

Maximum count of request retries. If no reply returns after a request had been sent, the station's status will change to a communication error.

-

2

Retry Timeout

Timeout before resending a request if no reply has been received.

ms

500

Wait First Timeout

The delay after sending the request and before reading the response.

ms

200

Wait Timeout

The delay between the reply readings.

ms

200

Max. Wait Retry

The maximum number of retries of the reply reading.

-

30

Send Valid Data Only

Send only valid data to the D2000 System. If it is set on YES, the Invalid values are not sent to the system.

YES/NO

YES

Future Data Filter

Filtering of data with a timestamp at least this value hours in the future. The setting to 0 hours disables this filter.

0-168 hours

24

History Data Filter

Filtering of data with a timestamp at least this value days in the past. The setting to 0 hours disables this filter.

0-730 days

31

Full debug

Extra debug information about communication on the line including debug information about all gained I/O tag values.

YES/NO

NO

I/O tag configuration

I/O tags for non-variable mode: Ai, Ci, TiA

I/o tag address:

Table 2 contains the list of supported I/O tag addresses. The address is in the text format - the value from the column "Address".

Table 2

Address

Value type

Tech. units

Meaning

VER

Ci

-

Protocol version (0x01).

ECSID

Ci

-

The ID of conversion device, it is numbered from 0.

RTURDTM

TiA

-

RTU  time of last reading the current data from the conversion devices.

ECSDTM

TiA

-

Time on the conversion device when the last reading the current data.

P

Ai

kPa

Current absolute pressure.

T

Ai

°C

Current temperature.

F

Ai

m3/hour

Instantaneous flow.

CLO

Ai

m3

Current status of the counter for the calculated quantity of LO.

CHI

Ai

m3

Current status of the counter for the calculated quantity of HI.

C

Ai

m3

Current status of counter for calculated quantity, calculated as C = 10000 * CHI + CLO.

C8LO

Ai

m3

Status of the counter for calculated quantity at 8:00 - LO.

C8HI

Ai

m3

Status of the counter for calculated quantity at 8:00 - HI.

C8

Ai

m3

Status of counter for calculated quantity at 8:00, calculated as C8 = 10000 * C8HI + C8LO.

VH

Ai

m3

Calculated quantity for the previous hour.

VD

Ai

m3

Calculated quantity for the previous day.