Reference, Installation, and Operations Manual

Section 2: Product overview

3-9000-743 Rev S

June 2013

 

 

 

Each group has a separate ground (i.e., Group1Gnd and Group 2 Gnd) and there is up to 50 V isolation between the two groups. Thus, all outputs within a group share a common ground. This allows each output group to be connected to a different flow computer. Daniel should be consulted before establishing the actual meter capacity for a particular application.

If outputs from both groups are to be connected to the same device, then the two group grounds must be connected together, either at the Daniel Mark III Ultrasonic Gas Flow Meter Field Connection Board or at the flow computer, whichever is more convenient.

All outputs are opto-isolated from the CPU Board (with a withstand of at least 500 Volt rms dielectric).

Each output is individually configurable as either internally powered (TTL) or externally powered (“open collector” e.g. O.C.). An output signal configured as “internally powered” is powered from an internal isolated 5 VDC bus and has voltage levels and drive capability as shown in Table 2-3.

Table 2-3 Voltage level and drive capability per logic level (TTL)
Logic ValueVoltage LevelDrive Capability

 

 

 

0

< 0.7 V

maximum sinking current:10 mA

 

 

 

1

> 3.5 V

maximum sourcing current:10 mA

 

 

 

An output signal configured as “open collector” (externally powered) must not exceed 60 VDC and must not be allowed to sink more than 50 mA.

Cable length TTL modeThe maximum cable length is 2000 feet when the “TTL” mode is selected.

Outputs

27