Emerson Process Management ControlWave EFM 3808 - Manual (Page 82)

2-30 / Installation & Operation CI-ControlWave EFM
2.3.4.2 I/O Wire Connections
ControlWave EFM electronic flow computers utilize compression-type terminals that
accommodate up to #14 AWG wire. A connection is made by inserting the wire’s bared end
(1/4” max) into the clamp beneath the screw and securing the screw. The wire should be
inserted fully so that no bare wires are exposed to cause shorts. If using standard wire, tin
the bare end with solder to prevent flattening and improve conductivity.
Allow some slack in the wires when making terminal connections. The slack makes the
connections more manageable and minimizes mechanical strain on the terminal blocks.
2.3.4.3 Shielding and Grounding
The use of twisted-pair, shielded and insulated cable for I/O signal wiring will minimize
signal errors caused by electromagnetic interference (EMI), radio frequency interference
(RFI) and transients. When using shielded cable, all shields should only be grounded at one
point in the appropriate system. This is necessary to prevent circulating ground current
loops that can cause signal errors.
2.3.4.4 Non-isolated Digital Input/Output Module (see Figure 2-19)
ControlWave EFM non-isolated Digital Input/Output Modules contain field interface
circuitry for up to 12 Digital Inputs and 4 Digital Outputs. Surge Suppression and signal
conditioning is provided for each DI. DO circuits consist of an open drain MOSFETs and
Surge Suppression. The DI filter time is 15 milliseconds. DI/O Modules con-sists of a Digital
Input/Output PCB with two 10-point Terminal Block Assemblies (for local termination), 14
Configuration Jumpers, an LED Board with 16 Status LEDs (one for each point) and a
Cover Assembly. The DI/O Board mates with the Backplane PCB via a 36-pin gold plated
card edge connector.
DI/O Modules provide internally sourced DI operation for Dry Contacts pulled internally to
3.3Vdc when the field input is open. Each DI is protected with a surge suppressor. DI
filtering is 15 milliseconds. The four DOs are composed of open drain MOSFETs and surge
suppressors. The DOs sink current to system ground of the DI/O Board.
2.3.4.4.1 Digital Input/Output Configurations
Digital Input/Output Modules provide 12 individually field configurable DIs and 4 non-
configurable externally powered DOs. Each DI may be individually set to provide either a
2mA or 60uA source current via Configuration Jumpers W1 through W12. Open drain
MOSFETs associated with each DO provide up 100mA each @ 30Vdc to an externally
powered device. DI/O Module Configuration Jumpers W1 through W14 must be set per
Table 2-8. Field wiring assignments are provided in Figure 2-19.
Table 2-8 - Non-Isolated DI/O Module Jumper Assignments
Jumper Purpose Notes
W1 - W12
Configures DI1 through
DI12 (respectively)
Pins 1-2 installed = 2mA Source Current
Pins 2-3 installed = 60uA Source Current
W13 LED Enable
Pins 1-2 installed = Enables LEDs Manually
Pins 2-3 installed = Enable LEDs via
software
W14 Program Serial EEPROM Factory Use ONLY